Weather synopsis

TEMPERATURE: This past week (June 7-13, 2021), weekly temperatures were above normal and rainfall in eastern Saskatchewan and Manitoba were above normal. The warmest temperatures were observed across Manitoba and Saskatchewan (Fig. 1). Across the prairies, the average 30-day (May 15 – June 13) temperature was 1 °C warmer than climate normal values. Warmest temperatures were observed across southern Manitoba (Fig. 2). The 2021 growing season (April 1 – June 13, 2021) has been characterized by near normal temperatures (Fig. 3).

Figure 1. 7-day average temperature (°C) observed across the Canadian prairies for the period of June 7 -13, 2021.
Figure 2. 30-day average temperature (°C) observed across the Canadian prairies for the period of May 15 – June 13, 2021.
Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1 – June 13, 2021.

Growing degree day (GDD) maps for Base 5 ºC and Base 10 ºC (April 1-Jun14, 2021) can be viewed by clicking the hyperlinks. Over the past 7 days (June 10-16, 2021), the lowest temperatures recorded across the Canadian prairies ranged from < -32 to >8 °C while the highest temperatures observed ranged from <19 to >35 °C. Access these maps and more using the AAFC Drought Watch webpage interface.

PRECIPITATION: This week, the highest rainfall amounts were reported across eastern Saskatchewan and most of Manitoba. Minimal rainfall was reported across most of Alberta (Fig. 4). Rainfall amounts for the period of May 15-June 13 (30-day accumulation) were above normal (150% of long-term average values). Rainfall amounts have been above normal for northeastern Alberta, northwestern and southeastern Saskatchewan, and western Manitoba. Well above normal rain was reported for Lloydminster, Regina, and Brandon regions. Below normal rainfall amounts were reported for the Peace River region and southern Alberta (Fig. 5). Average growing season (April 1 – June 13) precipitation was 116% of normal with the greatest precipitation occurring across eastern Saskatchewan, including Regina and an area extending from Brandon to Winnipeg. Below normal rainfall has been reported across western Saskatchewan and southern Alberta (Fig. 6).

Figure 4 . 7-day cumulative rainfall (mm) observed across the Canadian prairies for the period of June 7 -13, 2021.
Figure 5. 30-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 15 – June 13, 2021
Figure 6. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1-June 13, 2021.

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Weekly Wind Trajectory Report for June 15

Access background information for how and why wind trajectories are monitored in this post.

1. REVERSE TRAJECTORIES (RT)
Similar to last week, this week there were an increasing number of reverse trajectories moving north from the Pacific Northwest (Idaho, Oregon and Washington) (Fig. 1). Though this US region can be a source of diamondback moths (DBM), the ECCC models predict air movement, not actual occurrence of diamondback moths. Fields (and DBM traps) should be monitored for DBM adults and larvae.

Figure 1. The average number (based on a 5 day running average) of reverse trajectories that have crossed the prairies for the period of May 15 – June 15, 2021.

a. Pacific Northwest (Idaho, Oregon, Washington) – This week (June 11-15, 2021) there were 109 trajectories (versus 106 last week) that crossed Alberta, Manitoba and Saskatchewan (Fig. 2).

Figure 2. Total number of dates with reverse trajectories originating over the Pacific Northwest (Idaho, Oregon, and Washington) and have crossed the prairies between March 24 and June 15, 2021.

b. Mexico and southwest USA (Texas, California) – Compared to previous years, there has been a noticeable increase in number of trajectories from the southern US. The majority of these trajectories have crossed Manitoba and eastern Saskatchewan (Fig. 3). This week (June 11-15, 2021) there have been 11 trajectories (10 last week) that originated in Mexico or the southwest USA that have crossed the prairies.

Figure 3. The total number of dates with reverse trajectories originating over Mexico, California and Texas and have crossed the prairies between March 24 and June 15, 2021.

c. Oklahoma and Texas – The majority of these trajectories passed over Manitoba and eastern Saskatchewan (Fig. 4). This week (June 11-15, 2021) there were 18 trajectories (13 last week) originating in Oklahoma or Texas that passed over the prairies.

Figure 4. The total number of dates with reverse trajectories originating over Oklahoma and Texas and have crossed the prairies between March 24 and June 15, 2021.

d. Kansas and Nebraska – This week (June 11-15, 2021) there were 20 trajectories (19 last week) that originated in Kansas or Nebraska that passed over the prairies (Fig. 5).

Figure 5. The total number of dates with reverse trajectories originating over Kansas and Nebraska and have crossed the prairies between March 24 and June 15, 2021.

2. FORWARD TRAJECTORIES (FT)
a. This week there was a decrease in the number of forward trajectories predicted to cross the prairies (Fig. 6). The dates on the graph report when the trajectories originated in the USA (blue bars). These trajectories generally require 3-5 days to enter the prairies (red line). The data suggests that there will be increased potential for introduction of DBM to the prairies.

Figure 6. The average number (based on a 5 day running average) of forward trajectories that were predicted to cross the prairies for the period of May 15-June 15, 2021.

Weekly Wind Trajectory Report for June 10

Access background information for how and why wind trajectories are monitored in this post.

1. REVERSE TRAJECTORIES (RT)
This past week (in particular June 9 and 10) there were an increasing number of reverse trajectories moving north from the Pacific Northwest (Idaho, Oregon and Washington), Texas, Oklahoma, Kansas and Nebraska (Fig. 1). Though these US regions can be a source of diamondback moths (DBM), the ECCC models predict air movement, not actual occurrence of diamondback moths. Fields (and DBM traps) should be monitored for DBM adults and larvae.

Figure 1. The average number (based on a 5 day running average) of reverse trajectories that have crossed the prairies for the period of May 15 – June 10 2021.

a. Pacific Northwest (Idaho, Oregon, Washington) – This week there have been 106 trajectories (53 last week) that have crossed Alberta, Manitoba and Saskatchewan. This growing season, PNW trajectories have crossed all parts of the prairies (Fig. 2).

Figure 2. Total number of dates with reverse trajectories originating over the Pacific Northwest (Idaho, Oregon, and Washington) and have crossed the prairies between March 24 and June 10, 2021.

b. Mexico and southwest USA (Texas, California) – Compared to previous years, there has been a noticeable increase in the number of trajectories from the southern US. The majority of these trajectories have crossed Manitoba and eastern Saskatchewan (Fig. 3). This week there have been 10 trajectories (0 last week) that originated in Mexico or the southwest USA that have crossed the prairies (Fig. 3).

Figure 3. The total number of dates with reverse trajectories originating over Mexico, California and Texas and have crossed the prairies between March 24 and June 10, 2021.

c. Oklahoma and Texas – This week there have been 13 trajectories (0 last week) originating in Oklahoma or Texas that have passed over the prairies (Fig. 4).

Figure 4. The total number of dates with reverse trajectories originating over Oklahoma and Texas and have crossed the prairies between March 24 and June 10, 2021.

d. Kansas and Nebraska – This week there were 19 trajectories (versus 1 last week) that originated in Kansas or Nebraska that passed over the prairies (Fig. 5). Relative to the reverse trajectories associated with Oklahoma and Texas (Fig. 4), the trajectories from Kansas and Nebraska have crossed further into Alberta (Fig. 5).

Figure 5. The total number of dates with reverse trajectories originating over Kansas and Nebraska and have crossed the prairies between March 24 and June 10, 2021.

2. FORWARD TRAJECTORIES (FT)
a. Continuing a trend that began last week, this week there was an increase in the number of forward trajectories predicted to cross the prairies (Fig. 6). The dates on the graph report when the trajectories originated in the USA (blue bars). These trajectories generally require 3-5 days to enter the prairies (red line). The data suggests that there will be increased potential for introduction of DBM to the prairies.

Figure 6. The average number (based on a 5-day running average) of forward trajectories that were predicted to cross the prairies for the period of May 15-June 10, 2021.

Weather synopsis

TEMPERATURE: This past week (May 31 – June 6, 2021) extremely warm conditions resulted in weekly average temperatures that were well above normal (Fig. 1). The warmest temperatures were observed across Manitoba and eastern Saskatchewan (Fig. 1).

Figure 1. 7-day average temperature (°C) observed across the Canadian prairies for the period of May 31 – June 6, 2021.

Across the prairies, the average 30-day (May 8 – June 6) temperature was almost 2.5 °C warmer than the previous week and 1.3 °C greater than climate normal values. Warmest temperatures were observed across southern Manitoba (Table 1; Fig. 2).

Figure x. 30-day average temperature (°C) observed across the Canadian prairies for the period of May 8 – June 6, 2021.

The 2021 growing season (April 1 – June 6) has been characterized by near-normal temperatures. Temperatures have been warmest for southern Manitoba and southern Alberta (Table 2; Fig. 3).

Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1 – June 6, 2021.

Follow the hyperlinks to access AAFC Drought Watch maps reflecting the growing degree day (GDD) for Base 5 ºC, (April 1-June 7, 2021) and for Base 10 ºC (April 1-June 7, 2021). Over the past 7 days (June 3-9, 2021), the lowest temperatures recorded ranged from <0 to >12 °C while the highest temperatures observed across the Canadian prairies ranged from <10 to >36 °C.

PRECIPITATION: This week, the highest rainfall amounts were reported across northwest Saskatchewan and central Alberta while weekly rainfall amounts less than 2 mm was reported across a large area that extended from western Manitoba, across most of Saskatchewan, to southern Alberta. Extreme dry conditions were reported across the Peace River region (Fig. 4).

Figure 4 . 7 day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 31 – June 6, 2021.

Rainfall amounts for the period of May 8 to June 6 (30-day accumulation) were above normal (110 % of long-term average values). Rainfall amounts have been near normal to above normal for large areas of Alberta as well as northwest and southeast Saskatchewan. Well-above-normal rain was reported for Edmonton and Regina. Below normal rainfall amounts were reported for central and northern areas of the Peace River region and across Manitoba (Table 1; Fig. 5).

Figure 5. 30-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 8 – June 6, 2021.

Average growing season (April 1 – June 6) precipitation was 94 % of normal with the greatest precipitation occurring near Edmonton and across eastern Saskatchewan, including Regina. Most of Manitoba and the Peace River region have had 60 % or less than normal precipitation during the 2021 growing season (Table 2; Fig. 6).

Figure 6. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1 – June 6, 2021.

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Access ALL the PPMN’s Wind Trajectory reports (Weekly and Daily).

Access Environment and Climate Change Canada’s weather radar mapping interface. Options to access preceeding precipitation events include clicking off either an 1 or 3 hours time interval, using an 8-colour or 14-colour index. or changing the base map.

Predicted grasshopper development

Model simulations were used to estimate grasshopper (Melanoplus sanguinipes) development as of June 6, 2021. Average development of eggs is 86 % and is well ahead of the long term average of 73 %. Last week’s warm conditions across southeastern SK and southern Manitoba have been responsible for advanced development of eggs near Regina, Saskatoon, Brandon, and Winnipeg. Egg development is predicted to exceed 90 % across most of the southern prairies (Fig. 1).

Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development (%) across the Canadian prairies as of June 6, 2021.

As of June 6, hatch was predicted to be occurring across most of the prairies (overall average was 26 %) with hatch rates approaching 30-45 % across southern Manitoba and Saskatchewan (Fig. 2). The model was projected to June 22 to determine potential development at Regina and Swift Current over the next two weeks (Figs. 3 and 4). Results suggest that by June 22, Regina populations will primarily be in the third instar, with first appearance of fourth instars. Development near Swift Current is predicted to be slower, with populations being mostly in the first and second instars.

Warm, dry conditions continue to persist across Manitoba. This may result in conditions conducive to crop damage from grasshoppers as hatch progresses in June. Producers are advised to monitor roadsides and field margins to assess development and densities of local grasshopper populations.

Figure 2. Predicted grasshopper (Melanoplus sanguinipes) hatch (%) across the Canadian prairies as of June 6, 2021.
Figure 3. Predicted development of Melanoplus sanguinipes populations near Regina, Saskatchewan as of June 6, 2021 (projected to June 22, 2021).
Figure 4. Predicted development of Melanoplus sanguinipes populations near Swift Current, Saskatchewan as of June 6, 2021 (projected to June 22, 2021).

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture and Resource DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” (accessible in either English-enhanced or French-enhanced versions).

Weather synopsis

TEMPERATURE: This past week (May 24-30, 2021) the average temperature across the prairies was 1 °C cooler than normal (Fig. 1). Temperatures were warmest across most of Alberta and coolest across Saskatchewan and central regions of Manitoba. Across the prairies, the average 30-day (May 1-30) temperature was almost 2 °C warmer than last week and similar to climate normal values. Warmest temperatures were observed across southern Manitoba (Table 1; Fig. 2).

Figure 1. 7-day average temperature (°C) observed across the Canadian prairies for the period of May 24-30, 2021.
Figure 2. 30-day average temperature (°C) observed across the Canadian prairies for the period of May 1-30, 2021.

The 2021 growing season (April 1 – May 31) has been characterized by near-normal temperatures. Temperatures have been warmest for southern Manitoba, western Saskatchewan and southern Alberta (Table 2; Fig. 3).

Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1-May 30, 2021.

The growing degree day map (GDD) (Base 5 ºC, April 1-May 31, 2021) is provided below (Fig. 4) while the growing degree day map (GDD) (Base 10 ºC, April 1-May 31, 2021) is shown in Figure 5.

Figure 4. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-May 31, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (03Jun2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 5. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-May 31, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (03Jun2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Several areas were on the receiving end of frost and many folks are still watching to see how their crops recover. The lowest temperatures recorded ranged from <-14 to >0 °C (Fig. 6) while the highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <11 to >25 °C (Fig. 7).

Figure 6. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (May 27-Jun 2, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (03Jun2021) although PDF file format was not available. Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 7. Highest temperatures (°C) observed across the Canadian prairies the past seven days (May 27-Jun 2, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (03Jun2021) although PDF file format was not available. Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

PRECIPITATION: This week, significant precipitation was reported across central regions of Saskatchewan and Alberta while minimal rain was reported across Manitoba and western Alberta (Fig. 8). Rainfall amounts for the period of May 1-30 (30-day accumulation) were 123 % of long-term average values. Rainfall amounts have been near normal to above normal for large areas of Alberta and southern Saskatchewan. Well above normal rain was reported for Edmonton and Regina. Below normal rainfall amounts were reported for central and northern areas of the Peace River region and across Manitoba (Table 1; Fig. 9).

Figure 8. 7-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 24-30, 2021.
Figure 9. 30-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 1-30, 2021.

Average growing season (April 1 – May 30) precipitation was 105 % of normal with the greatest precipitation occurring near Edmonton and across eastern Saskatchewan. Most of Manitoba and the Peace River region have had 60 % or less of normal precipitation during the 2021 growing season so far (Table 2; Fig. 10).

Figure x. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1-May 30, 2021.

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Access ALL the PPMN’s Wind Trajectory reports (Weekly and Daily).

Access Environment and Climate Change Canada’s weather radar mapping interface. Options to access preceeding precipitation events include clicking off either an 1 or 3 hours time interval, using an 8-colour or 14-colour index. or changing the base map.

Weekly Wind Trajectory Report for June 3

Access background information for how and why wind trajectories are monitored in this post.

1. REVERSE TRAJECTORIES (RT)
This past week there were an increasing number of reverse trajectories moving north from the Pacific Northwest (Idaho, Oregon and Washington) (Fig. 1). Though this US region can be a source of diamondback moths, the ECCC models predict air movement, not actual occurrence of diamondback moths.

Figure 1. The average number (based on a 5 day running average) of reverse trajectories that have crossed the prairies for the period of May 15 – June 3 2021.

a. Pacific Northwest (Idaho, Oregon, Washington) – This week there were 53 trajectories (compared to 36 last week) that crossed Alberta, Manitoba and Saskatchewan. In previous years, the majority of Pacific Northwest reverse trajectories usually have been reported to pass over southern Alberta. However, tis growing season, PNW trajectories have crossed all parts of the prairies (Figs. 2 and 3).

Figure 2. Total number of reverse trajectories originating across Idaho, Oregon, and Washington and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 3. Total number of dates with reverse trajectories originating over the Pacific Northwest (Idaho, Oregon, and Washington) and have crossed the prairies between March 24 and June 3, 2021.

b. Mexico and southwest USA (Texas, California) – Compared to previous years, there has been a noticeable increase in the number of trajectories from the southern US. The majority of these trajectories have crossed Manitoba and eastern Saskatchewan (Fig. 4). This week there were no trajectories (compared to 54 last week) that originated in Mexico or the southwest USA that crossed the prairies (Fig. 5).

Figure 4. Total number of reverse trajectories originating across Mexico, California and Texas and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 5. The total number of dates with reverse trajectories originating over Mexico, California and Texas and have crossed the prairies between March 24 and June 3, 2021.

c. Oklahoma and Texas – The majority of these trajectories have passed over Manitoba and eastern Saskatchewan (Fig. 6). This week there were no trajectories (compared to 51 last week) originating in Oklahoma or Texas that passed over the prairies (Fig. 7).

Figure 6. Total number of reverse trajectories originating across Oklahoma and Texas and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 7. The total number of dates with reverse trajectories originating over Oklahoma and Texas and have crossed the prairies between March 24 and June 3, 2021.

d. Kansas and Nebraska – Similar to results for Oklahoma and Texas, the majority of these trajectories crossed Manitoba and eastern Saskatchewan (Fig. 8). This week there was one trajectory that originated in Kansas or Nebraska that passed over Carman, Manitoba (Fig. 9). Relative to the reverse trajectories associated with Oklahoma and Texas, the trajectories from Kansas and Nebraska have crossed further into Alberta (Fig. 9).

Figure 8. Total number of reverse trajectories originating across Kansas and Nebraska and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 9. The total number of dates with reverse trajectories originating over Kansas and Nebraska and have crossed the prairies between March 24 and June 3, 2021.

2. FORWARD TRAJECTORIES (FT)
a. Continuing a trend that began last week, this week there was a decrease in the number of forward trajectories that were predicted to cross the prairies (Fig. 10). The dates on the graph report when the trajectories originated in the USA (blue bars). These trajectories generally require 3-5 days to enter the prairies (red line). The data suggests that, compared to this week, there will be decreased potential for the introduction of DBM to the prairies.

Figure 10. The average number (based on a 5-day running average) of forward trajectories that were predicted to cross the prairies for the period of May 15-June 3, 2021.

Weekly Wind Trajectory Report for May 28

Access background information for how and why wind trajectories are monitored in this post.

1. REVERSE TRAJECTORIES (RT)
Since May 1, 2021 the majority of reverse trajectories that have crossed the prairies originated from the Pacific Northwest (Idaho, Oregon and Washington). For the past two weeks there have been an increasing number of reverse trajectories that moved north from Texas, Oklahoma, Kansas and Nebraska (Fig. 1). Compared to previous years, the number incoming trajectories (May) has increased. Though these US regions can be a source of diamondback moths, the ECCC models predict air movement, not actual occurrence of diamondback moths. It should also be noted that host plants of diamondback moth include all plants in the Brassicacea family, including cruciferous weeds and volunteer canola. These plants are suitable hosts until canola emerges.

Figure 1. The average number (based on a 5 day running average) of reverse trajectories that have crossed the prairies for
the period of May 1 – 27 2021.

a. Pacific Northwest (Idaho, Oregon, Washington) – This week there have been 36 trajectories (44 last week) that have crossed Alberta, Manitoba and Saskatchewan. In previous years, the majority of Pacific Northwest reverse trajectories usually have been reported to pass over southern Alberta. This growing season, PNW trajectories have crossed all parts of the prairies (Fig. 2). Compared to this time last year there has been a significant increase in the number of trajectories that have crossed Manitoba and eastern Saskatchewan.

Figure 2. Total number of dates with reverse trajectories originating over Pacific Northwest (Idaho, Oregon, and Washington) and
have crossed the prairies between March 24 and May 27, 2021.

b. Mexico and southwest USA (Texas, California) – Compared to previous years, there has been a noticeable increase in number of trajectories from the southern US. This week there have been 54 trajectories (15 last week) that originated in Mexico and the southwestern US that have crossed the prairies (Fig. 3).

Figure 3. The total number of dates with reverse trajectories originating over Mexico, California and Texas and have
crossed the prairies between March 24 and May 27, 2021.

c. Oklahoma and Texas – This week there have been 51 trajectories (16 last week) that have passed over Manitoba, Saskatchewan and eastern Alberta that originated in Oklahoma or Texas (Fig. 4).

Figure 4. The total number of dates with reverse trajectories originating over Oklahoma and Texas and have crossed
the prairies between March 24 and May 27, 2021.

d. Kansas and Nebraska – This week there have been 63 trajectories (35 last week) that originated in Kansas or Nebraska that have passed over the prairies (Fig. 5). Relative to the reverse trajectories associated with Oklahoma and Texas, the trajectories from Kansas and Nebraska have crossed further into Alberta.

Figure 5. The total number of dates with reverse trajectories originating over Kansas and Nebraska and have crossed
the prairies between March 24 and May 27, 2021.

2. FORWARD TRAJECTORIES (FT)
a. Forward trajectories, originating from Mexico and USA, have crossed a number of prairie locations since May 1, 2021. This week there has been a decrease in the number of trajectories that are predicted to cross the prairies (Fig. 6). The dates on the graph report when the trajectories originated in the USA (blue bars). These trajectories generally require 3-5 days to enter the prairies (red line). The data suggests that, compared to this week, there may be increased potential for the introduction of DBM to the prairies.

Figure 6. The average number (based on a 5-day running average) of forward trajectories that have crossed
the prairies for the period of May 1- 27, 2021.

Weather synopsis

TEMPERATURE: This past week (May 17-23, 2021) began with hot dry conditions followed by cool/wet conditions (mid-week reports of snow and minimum temperatures less than 0 °C). Most of the prairies had significant rainfall over the weekend. The average temperature across the prairies was 1 °C cooler than normal (Fig. 1). For the second week temperatures were warmest across Manitoba. Temperatures were coolest across western Saskatchewan and most of Alberta.

Figure 1. 7-day average temperature (°C) observed across the Canadian prairies for the period of May 17-23, 2021.

The prairie-wide average 30-day temperature (April 24- May 23) was 0.4 °C less than climate normal values. The warmest temperatures were observed across the southern prairies (Table 1; Fig. 2). The 2021 growing season (April 1 – May 16) has been characterized by near-normal temperatures. Temperatures have been similar across the prairies (Table 2; Fig. 3).

Figure 2. 30-day average temperature (°C) observed across the Canadian prairies for the period of April 24-May 23, 2021.
Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1-May 23, 2021.

The growing degree day map (GDD) (Base 5 ºC, April 1-May 24, 2021) is provided below (Fig. 4) while the growing degree day map (GDD) (Base 10 ºC, April 1-May 24, 2021) is shown in Figure 5.

Figure 4. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-May 24, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (27May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 5. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-May 24, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (27May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Many were uttering the f-word this past week… several areas were on the receiving end of frost and many folks are still watching to see how their crops recover. The lowest temperatures recorded ranged from <-14 to >0 °C (Fig. 6) while the highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <11 to >25 °C (Fig. 7).

Figure 6. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (May 20-26, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (27May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 7. Highest temperatures (°C) observed across the Canadian prairies the past seven days (May 12-18, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (19May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

PRECIPITATION: This week average precipitation for the prairies was 17 mm (Fig. 8). Last week the average was less than 2 mm. Conditions continued to be dry in a large region bounded by Swift Current, Saskatoon and Vegreville as well as central and northern areas of the Peace River region. Rainfall amounts for the period of April 24-May 23 (30-day accumulation) were 88 % of long-term average values. Rainfall was greatest for large areas of Alberta, southern Saskatchewan and southern Manitoba (Table 1; Fig. 9). Average growing season (April 1 – May 23) precipitation was 86 % of normal (Table 1; Fig. 10). The map indicates that conditions continue to be very dry across the Peace River region, east-central Alberta, and west-central Saskatchewan.

Figure 8. 7-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 17-23, 2021.
Figure 9. 30-day cumulative rainfall (mm) observed across the Canadian prairies for the period of April 24-May 23, 2021.
Figure 10. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1-May 23, 2021.

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Access ALL the PPMN’s Wind Trajectory reports (Weekly and Daily).

Access Environment and Climate Change Canada’s weather radar mapping interface. Options to access preceeding precipitation events include clicking off either an 1 or 3 hours time interval, using an 8-colour or 14-colour index. or changing the base map.

Weekly Wind Trajectory Report for May 20

Access background information for how and why wind trajectories are monitored in this post.

1. REVERSE TRAJECTORIES (RT)
Since May 1, 2021 the majority of reverse trajectories that have crossed the prairies originated from the Pacific Northwest (Idaho, Oregon and Washington). This week there have been an increasing number of reverse trajectories that moved north from Texas, Oklahoma and Kansas and Nebraska (Fig. 1). Though these US regions can be a source of diamondback moths, the ECCC models predict air movement, not actual occurrence of diamondback moths. It should also be noted that host plants of diamondback moth include all plants in the Brassicacea family, including cruciferous weeds and volunteer canola. These plants are suitable hosts until canola emerges.

Figure 1. The average number (based on a 5 day running average) of reverse trajectories that have crossed the prairies for
the period of May 1- 20, 2021.

a. Pacific Northwest (Idaho, Oregon, Washington) – This week there have been 44 trajectories (27 last week) that have crossed Alberta, Manitoba, and Saskatchewan. The majority of Pacific Northwest reverse trajectories usually have been reported to pass over southern Alberta. This growing season, PNW trajectories have crossed all of the prairies (Fig. 2).

Figure 2. Total number of dates with reverse trajectories originating over Pacific Northwest (Idaho, Oregon, and Washington) and have
crossed the prairies between March 24 and May 20, 2021.

b. Mexico and southwest USA (Texas, California) – This week there have been 15 trajectories that originated in Mexico and the southwestern US that have crossed Manitoba and Saskatchewan.

c. Oklahoma and Texas – This week there have been 16 trajectories that have passed over Manitoba and Saskatchewan (Fig. 3) that originated in Oklahoma or Texas. These are the first trajectories, that originated over Oklahoma and Texas, to enter the prairies during the month of May.

Figure 3. The total number of dates with reverse trajectories originating over Oklahoma and Texas and have crossed the
prairies between March 24 and May 20, 2021.

d. Kansas and Nebraska – This week there have been 35 trajectories (8 last week) that originated in Kansas or Nebraska that have passed over Manitoba and Saskatchewan (Fig. 4).

Figure 4. The total number of dates with reverse trajectories originating over Kansas and Nebraska and have crossed the
prairies between March 24 and May 20, 2021.

2. FORWARD TRAJECTORIES (FT)
a. Forward trajectories, originating from Mexico and USA, have crossed a number of prairie locations since May 1, 2021. This week, there has been a steady increase in the number of trajectories that are predicted to cross the prairies (Fig. 5). The dates on the graph report when the trajectories originated in the USA (blue bars). These trajectories generally require 3-5 days to enter the prairies (red line). The data suggests that, compared to this week, there may be increased potential for the introduction of DBM to the prairies.

Figure 5. The average number (based on a 5 day running average) of forward trajectories that have crossed the
Canadian prairies for the period of May 1- 20, 2021.

The following map presents the total number of forward trajectories that have crossed the Canadian prairies (since March 24, 2021) (Fig. 6). Results indicate that the greatest number of forward trajectories entering Canada originated from the Pacific Northwest (Idaho, Oregon, Washington).

Figure 6. The total number of dates with forward trajectories, originating from various regions of the United States and
Mexico, crossed the prairies between March 24 and May 20, 2021.

Earlier in the week, an Alert related to wind trajectories assessed over May 18-19, 2021, was shared by the PPMN. It communicated the anticpated arrival of several air masses arriving across the Canadian prairies over the next few days that originated from multiple areas of USA. Remember, the current WEEKLY REPORT (above) summarizes daily data over a longer, more comprehensive period.

Weather synopsis

TEMPERATURE: This past week the average temperature across the prairies was 2.5 °C warmer than normal (Fig. 1). Temperatures were warmest across the Parkland region in Manitoba, Saskatchewan, and Alberta.

Figure 1. 7-day average temperature (°C) observed across the Canadian prairies for the period of May 10-16, 2021.

The prairie-wide average 30-day temperature (April 17- May 16) was 0.9 °C less than climate normal values. A region from Winnipeg to Saskatoon has been 2 to 4 °C cooler than average. Temperatures have been warmest across southern Alberta (Table 1; Fig. 2).

Figure 2. 30-day average temperature (°C) observed across the Canadian prairies for the period of April 17-May 16, 2021.

The 2021 growing season (April 1 – May 16) has been characterized by near normal temperatures. Warmest temperatures were observed in a region between Lethbridge, Saskatoon and Edmonton while coolest temperatures were reported from Manitoba (Table 2; Fig. 3).

Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1-May 16, 2021.

The growing degree day map (GDD) (Base 5 ºC, April 1-May 2, 2021) is provided below (Fig. 4) while the growing degree day map (GDD) (Base 10 ºC, April 1-August 9, 2020) is shown in Figure 5.

Figure 4. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-May 17, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (19May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 5. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-May 17, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (19May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

At this early point in the growing season, cool temperatures pose the risk of frost but the differences between low and high temperatures can exert stress on plants, particularly when field conditions are dry. The lowest temperatures recorded ranged from <-8 to >6 °C (Fig. 6) while the highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <3 to >28 °C (Fig. 7).

Figure 6. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (May 12-18, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (19May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 7. Highest temperatures (°C) observed across the Canadian prairies the past seven days (May 12-18, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (19May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

PRECIPITATION: Seven-day cumulative rainfall amounts indicate that most of the prairies had less than 2 mm of rain in the past week (Fig. 8). Rainfall amounts for the period of April 17-May 16 (30-day accumulation) were 56 % of long-term average values. Rainfall was greatest for southwestern Saskatchewan and across most of Alberta (Table 1; Fig. 9).

Figure 8 . 7-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 10-16, 2021.
Figure 9. 30 day cumulative rainfall (mm) observed across the Canadian prairies for the period of April 17-May 16, 2021.

Average growing season (April 1 – May 16) precipitation has been well below average for most of the prairies (35 % less than normal). Saskatoon has reported 4.3 mm (15 % of normal) and most of Saskatchewan and Manitoba have had less than 15 mm (40 % of normal precipitation) (Table 1; Fig. 10).

Figure 10. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1-May 16, 2021.

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Access ALL the PPMN’s Wind Trajectory reports (Weekly and Daily).

Access Environment and Climate Change Canada’s weather radar mapping interface. Options to access preceding precipitation events include clicking off either an 1 or 3 hours time interval, using an 8-colour or 14-colour index. or changing the base map.

ALERT – Wind Trajectory Report for May 19

Access background information for how and why wind trajectories are monitored in this earlier post.

Alert: Yesterday and today ECCC models produced results that suggest a number of RT’s for prairie locations. Compared to previous dates, the ECCC model output predicts that trajectories are passing almost the entire prairie region over a very short period of time. The weather forecast may result in downward movement of DBM.

Details: There has been a significant increase in the number of trajectories, originating over a number of states in the USA, that have crossed the prairies (Fig. 1). These air currents may introduce diamondback moths to the prairies. ECCC trajectory models indicate that air trajectories, originating over the Pacific Northwest (Idaho, Oregon, Washington), have crossed Alberta, Saskatchewan and western Manitoba (Fig. 2). Trajectories originating over Texas and Oklahoma have passed over eastern Saskatchewan and Manitoba (Fig. 3). A third group of trajectories, originating across Kansas and Nebraska have also crossed eastern Saskatchewan and Manitoba (Fig. 4).

Though these US regions can be a source of diamondback moths, the ECCC models predict air movement, not actual occurrence of diamondback moths. It should also be noted that host plants of diamondback moth include all plants in the Brassicaceae family, including cruciferous weeds and volunteer canola. These plants are suitable hosts until canola emerges.

Action: The ECCC model output predicts that trajectories are passing almost the entire prairie region over a very short period of time. Areas highlighted in green in Figures 2, 3, and 4 of this alert may receive downward movement of DBM very shortly. The presence of any Brassicaceae plant will provide a host for incoming DBM so scout volunteers and emerging canola. If DBM were carried north on air currents it may take a few days for DBM to show up in traps.

Figure 1. Summary of the average number (5 day running average) of reverse trajectories that have crossed the Canadian prairies (May 1-19, 2021) 
Figure 2. The green region indicates the potential for introduction of diamondback moths from the Pacific Northwest (Idaho, Oregon, and Washington) to the Canadian prairies (May 18-19, 2021).
Figure 3. The green region indicates the potential for introduction of diamondback moths from Texas and Oklahoma to
the Canadian prairies (May 18-19, 2021).
Figure 4. The green region indicates the potential for introduction of diamondback moths from Kansas and Nebraska to the Canadian prairies (May 18-19, 2021).

Weather synopsis

Since April 1, the 2021 growing season has been cooler and dryer than normal. The National Agroclimate Risk Report states that the most significant climate-related risk to agriculture is the dry conditions across the prairie region (access the Spring to April 27, 2021 report).

This past week (May 3-9, 2021), the average temperature across the prairies was 1.3 °C cooler than normal (Fig. 1). Similarly, the average 30-day temperature (April 10-May 9) was 1.7 °C less than climate normal values (Fig. 2). Temperatures have been warmest in southern Alberta (Table 1; Fig. 1-2).

Figure 1. Seven-day average temperature (°C) across the Canadian prairies for the period of May 3-9, 2021.
Figure 2. 30-day average temperature (°C) across the Canadian prairies for the period of April 10-May 9, 2021.

The growing degree day map (GDD) (Base 5 ºC, April 1-May 2, 2021) is provided below (Fig. 3) while the growing degree day map (GDD) (Base 10 ºC, April 1-August 9, 2020) is shown in Figure 4.

Figure 3. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-May 11, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 4. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-May 11, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

At this early point in the growing season, cool temperatures pose the risk of frost but the differences between low and high temperatures can exert incredible stress on newly germinating plants in field crops. The lowest temperatures recorded ranged from <-59 to >-6 °C (Fig. 5) while the highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <11 to >26 °C (Fig. 6). Wow, what an amazing range – spring is tough!

Figure 5. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (May 5-11, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 6. Highest temperatures (°C) observed across the Canadian prairies the past seven days (May 5-11, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Seven-day cumulative rainfall indicates that below normal rain (86% of average) was reported for the prairies (Fig. 7). Over the past seven-days rain totals across most of Alberta and the extreme southwest region of Saskatchewan was 10-20 mm. The rest of the prairies received little or no rain. Rain (30-day accumulation) amounts have been less than average for most of the prairies (81% of average). Rainfall for April 10-May 9, 2021, has been greatest for southeastern Manitoba, southwestern Saskatchewan and across most of Alberta (Table 1; Fig. 8). Average growing season (April 1 to May 9) precipitation has been well below average for most of the prairies. The two large regions (Swift Current to Prince Albert to Vegreville and the western two-thirds of Manitoba) have had less than 40 % of normal precipitation.

Figure 7. Seven-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (May 3-9, 2021).
Figure 8. 30-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (April 10-May 9, 2021).

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Access ALL the PPMN’s Wind Trajectory reports (Weekly and Daily).

Access Environment and Climate Change Canada’s weather radar mapping interface.

Potential of trajectories for monitoring insect movements

Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth. In addition, plant pathologists have shown that trajectories can assist with the prediction of plant disease infestations and are also beginning to utilize these same data. We receive two types of model output from ECCC: reverse trajectories and forward trajectories.

‘Reverse trajectories’ refer to air currents that are tracked back in time from specified Canadian locations over a five-day period prior to their arrival date. Of particular interest are those trajectories that, prior to their arrival in Canada, originated over northwestern and southern USA and Mexico, anywhere diamondback moth populations overwinter and adults are actively migrating. If diamondback adults are present in the air currents that originate from these southern locations, the moths may be deposited on the Prairies at sites along the trajectory, depending on the local weather conditions at the time that the trajectories pass over our area (e.g. rain showers, etc.). Reverse trajectories are the best available estimate of the ”true” 3D wind fields at a specific point. They are based on observations, satellite and radiosonde data.

‘Forward trajectories’ have a similar purpose; however, the modeling process begins at sites in USA & Mexico. The model output predicts the pathway of a trajectory. Again, of interest to us are the winds that eventually end up passing over the Prairies.

Access all the Historical Wind Trajectory Reports.

Weiss1, Vankosky1, Trudel2
1 Agriculture and Agri-Food Canada
2 Environment and Climate Change Canada

Weekly Wind Trajectory Report (released May 13)

Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth. Read a brief overview of this strategy plus the definitions and applications of both ‘Reverse’ and ‘Forward’ trajectories.

1. REVERSE TRAJECTORIES (RT)
Since May 1, 2021, the majority of reverse trajectories crossing the prairies originated from the Pacific Northwest (Idaho, Oregon and Washington). This week, an increasing number of reverse trajectories have been moving north from Kansas and Nebraska (Fig. 1).

Figure 1. The average number (based on a 5-day running average) of reverse trajectories (RTs) that have
crossed the prairies for the period of May 1-13, 2021.

a. Pacific Northwest (Idaho, Oregon, Washington) – The majority of Pacific Northwest reverse trajectories have been reported to pass over southern Alberta (Fig. 2).

Figure 2. Total number of dates with reverse trajectories originating over the Pacific Northwest (PNW including Idaho, Oregon, and Washington) that have crossed the prairies between March 24 and May 13, 2021.

b. Mexico and southwest USA (Texas, California) – Since last week there have not been any trajectories that originated in these areas that have crossed the prairies.

c. Oklahoma and Texas – Since last week there have not been any trajectories originating in Oklahoma or Texas that have crossed the prairies.

d. Kansas and Nebraska – This week reverse trajectories were reported for Alberta (Andrew, Sedgewick), Saskatchewan (Gainsborough, Grenfell, Kindersley, Regina, Yorkton) and Manitoba (Brandon) (Fig. 3).

Figure 3. The total number of dates with reverse trajectories originating over Kansas and Nebraska that have crossed the
prairies between March 24 and May 13, 2021.

2. FORWARD TRAJECTORIES (FT)
Forward trajectories, originating from Mexico and USA have crossed a number of prairie locations since May 1, 2021. Based on average totals (averaged across a five day period), the greatest number of forward trajectories were observed to originate between May 5 and 8 (blue bars) and entered the prairies between May 6-9 (Fig. 4).

Figure 4. The average number (based on a 5 day running average) of forward trajectories that have crossed the
prairies for the period of May 1- 13, 2021.

The following map presents the total number of dates (since March 24, 2021) with forward trajectories that have crossed the Canadian prairies (Fig. 5). Results indicate that the greatest number of forward trajectories entering Canada originated from the Pacific Northwest (Idaho, Oregon, Washington).

Figure 5. The total number of dates with forward trajectories, originating from various regions of the United States and Mexico, that crossed the prairies between March 24 and May 13, 2021.

Access a PDF version of the full WEEKLY report released May13, 2021.

Wind Trajectory Report for May 10

ECCC trajectory models indicate that air trajectories, originating over the Pacific Northwest (Idaho, Oregon, Washington), have crossed one Saskatchewan location (Unity) and a number of Alberta locations including Lethbridge, Beiseker, Olds, Provost, Vegreville, Andrew, Grande Prairie, Rycroft and Fort Vermillion.

Access this DAILY one-page report to learn more. Albertans and Saskatchewanians please take note!

Areas highlighted green in this alert may receive incoming winds from the Pacific Northwest of the USA very shortly! Remember, host plants of diamondback moth include all plants in the Brassicacea family, including cruciferous weeds and volunteer canola. These plants are suitable hosts until canola emerges. 

ALERT – Wind Trajectory Report for May 7

Environment and Climate Change Canada (ECCC) trajectory models indicate that air trajectories, originating over the Pacific Northwest (Idaho, Oregon, Washington), have crossed a number of Alberta locations including Lethbridge, Beiseker, Olds, Manning, Rycroft, and Wanham.

Access this special one-page alert to learn more. Albertans please take note!

Action: Areas highlighted green in this alert may receive incoming winds from the Pacific Northwest of the USA very shortly so please deploy diamondback pheromone traps as soon as possible!

Weather synopsis

Since April 1, the 2021 growing season has been cooler and dryer than normal. This past week (April 26-May 2, 2021), the average temperature across the prairies was approximately 0.5 °C cooler than normal. Similarly, the average 30-day temperature (April 3- May 2) was 0.6 °C less than climate normal values. Temperatures have been warmest in southern Alberta. Seven day cumulative rainfall indicates that below normal rain (79% of average) was reported for the prairies.

Figure 1. 7-day average temperature (°C) across the Canadian prairies for the period of April 26-May 2, 2021.
Figure 2. 30-day average temperature (°C) across the Canadian prairies for the period of April 3-May 2, 2021.

The growing degree day map (GDD) (Base 5 ºC, April 1-May 2, 2021) is below (Fig. 3) while the growing degree day map (GDD) (Base 10 ºC, April 1-August 9, 2020) is shown in Figure 4.

Figure 3. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-May 3, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 4. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-May 3, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

At this early point in the growing season, cool temperatures pose the risk of frost but the differences between low and high temperatures can exert incredible stress on newly germinating plants in field crops. The lowest temperatures ranged from <-14 to >0 °C (Fig. 5) while the highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <3 to >24 °C (Fig. 6).

Figure 5. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (April 29-May 5, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 6. Highest temperatures (°C) observed across the Canadian prairies the past seven days (April 29-May 5, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (06May2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Rain (30-day accumulation) amounts have been less than average for most of the prairies (75 % of average; Fig. 7). Rainfall for April 3-May 2, 2021, has been greatest for southeastern Manitoba and the extreme southwest of Alberta (Fig. 8).

Figure 7. 30-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (April 1-May 2, 2021).
Figure 8. Seven-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (April 26-May 2, 2021).

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network.

Access the PPMN’s Weekly Wind Trajectory report released May 5, 2021.

FYI: Environment and Climate Change Canada updated the weather radar mapping interface recently.

Weekly Wind Trajectory Report (released May 5)

Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth.

Access a PDF version of the full report for May 5, 2021.

Weather synopsis

An abbreviated synopsis is provided for the final Weekly Update of the 2020 growing season. It was a warm week for most of the prairies! The highest temperatures the past seven days across the prairies are represented in Figure 1 and ranged from <22 to >35 °C.

Figure 1. Highest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-August 19, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

All those high temperatures advanced the accumulation of heat units across the prairies. The growing degree day map (GDD) (Base 5 ºC, April 1-August 17, 2020) is below (Fig. 2) while the growing degree day map (GDD) (Base 10 ºC, April 1-August 17, 2020) is shown in Figure 3.

Figure 2. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-August 17, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 3. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-August 17, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

So far this growing season, the number of days above 25 °C ranges from 0-10 days in the northwest of the prairies then increases up to 61-70 days in southern Manitoba (Fig. 4). In comparison, the number of days above 30 °C ranges up to 25-27 days in southern Saskatchewan and southern Manitoba (Fig. 5)

Figure 4. Number of days above 25 °C observed across the Canadian prairies this growing season (April 1-August 19, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 5. Number of days above 30 °C observed across the Canadian prairies this growing season (April 1-August 19, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

As fields continue to mature in late August and in to September, growers will be watching for cool evenings. The lowest temperatures the past seven days across the prairies are represented in Figure 6 and ranged from <1 to >13 °C.

Figure 6. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-August 19, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

Cumulative rainfall for the past 7 days was lowest across central and southern regions of Alberta and Saskatchewan while western and northern areas of the Peace River region AND eastern Saskatchewan plus much of Manitoba received more moisture (Fig. 7). Cumulative 30-day (Fig. 8) and rainfall for the growing season (April 1-August 19, 2020; Fig. 9) are below.

Figure 7. Observed cumulative precipitation across the Canadian prairies the past seven days (as of August 19, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 8. Observed cumulative precipitation across the Canadian prairies the past 30 days (as of August 19, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 9. Observed cumulative precipitation across the Canadian prairies for the growing season (as of August 19, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (20Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Drought Watch Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch website, Environment Canada’s Historical Data website, or your provincial weather network.

Weather synopsis

This past week (Aug 4-10, 2020) conditions were generally warm and dry. Weekly prairie temperatures were warmest across Manitoba and Saskatchewan (Fig. 1). Lower temperatures were observed across western and northwestern Alberta (Fig. 1). Though average 30-day (July 12 – August 10, 2020) temperatures continue to be cooler in Alberta than eastern Saskatchewan and Manitoba (Fig. 2), temperature anomalies (mean temperature difference from average; July 14-August 10, 2020) indicate that conditions have generally been warmer than average across most of Alberta as well as Parkland regions of Saskatchewan and Manitoba (Fig. 3).

Figure 1. Observed average temperatures across the Canadian prairies the past seven days (August 4-10, 2020).
Figure 2. Observed average temperatures across the Canadian prairies the past 30 days (July 12-August 10, 2020).
Figure 3. Mean temperature difference from Normal the past 30 days (July 14-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

Regions in southeastern central and southern Saskatchewan and across southern Manitoba have reported temperatures that have been up to 2 °C cooler than average. Based on growing season temperatures (April 1-August 10, 2020) temperatures were warmest across the southern prairies (Fig. 4). Based on growing season temperature deviations (observed temperatures compared with climate normal temperatures), below average temperatures have been observed across central and western regions of Saskatchewan and central regions of Alberta (Fig. 5). Across southern Alberta and most of Manitoba, temperatures have generally been above average. (Fig. 5)

Figure 4. Observed average temperatures across the Canadian prairies for the growing season (April 1-August 10, 2020).
Figure 5. Observed difference from average temperatures across the Canadian prairies for the growing season (April 1-August 10, 2020).

Most areas reported 7-day cumulative rainfall amounts that were less than 10 mm (Fig. 6). Cumulative 30-day rainfall was lowest across a large area ranging across southern Alberta as well as central and western regions of Saskatchewan (Fig. 7). Growing season rainfall (percent of average) is highly variable across the prairies (Fig. 8). Rainfall has been below normal across most of Saskatchewan as well as southern Alberta, and the Peace River region (Fig. 8).

Figure 6. Observed cumulative precipitation across the Canadian prairies the past seven days (August 4-10, 2020).
Figure 7. Observed cumulative precipitation across the Canadian prairies the past 30 days (July 12-August 10, 2020).
Figure 8. Percent of average precipitation for the growing season (April 1-August 10, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (12Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The growing degree day map (GDD) (Base 5 ºC, April 1-August 9, 2020) is below (Fig. 9) while the growing degree day map (GDD) (Base 10 ºC, April 1-August 9, 2020) is shown in Figure 10.

Figure 9. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-August 9, 2020).
Figure 10. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-August 9, 2020).

The highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <17 to >34 °C (Fig. 11) while the lowest temperatures ranged from <-1 to >13 °C (Fig. 12). So far this growing season (as of August 12, 2020), the number of days above 25 °C ranges from 0-10 days in the west (to west of Calgary, west and north of central Alberta and extending into the south and west of the Peace River region) but extends up to 51-60 days in southern Manitoba (Fig. 13).

Figure 11. Highest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 12. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 13. Number of days above 25 °C observed across the Canadian prairies this growing season (April 1-August 12, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Aug2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Drought Watch Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch website, Environment Canada’s Historical Data website, or your provincial weather network.

Weather synopsis

An abbreviated synopsis of the past week is provided below. Recent warm weather across the Canadian prairies helped crop development this past week

The growing degree day map (GDD) (Base 5 ºC, April 1-July 27, 2020) is below (Fig. 1) while the growing degree day map (GDD) (Base 10 ºC, April 1-July 27, 2020) is shown in Figure 2.

Figure 1. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-July 27, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (30Jul2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 2. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-July 27, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (30Jul2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <22 to >34 °C (Fig. 3). So far this growing season (up to July 29, 2020), the number of days above 25 ranges from 0-10 days throughout much of Alberta and into the BC Peace then extends up to 41-50 days in southern Manitoba (Fig. 4).

Figure 3. Highest temperatures (°C) observed across the Canadian prairies the past seven days (April 1-July 29, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (30Jul2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 4. Number of days above 25 °C observed across the Canadian prairies this growing season (April 1-July 29, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (30Jul2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

Cumulative rainfall for the past 7 days was lowest across southern regions of Alberta, Saskatchewan, and Manitoba with the exception of around Regina south to the American border, and southwest Manitoba west into the southeast corner of Saskatchewan (Fig. 5). Cumulative 30-day (Fig. 6) and rainfall for the growing season (April 1-July 29, 2020; Fig. 7) are below.

Figure 5. Observed cumulative precipitation across the Canadian prairies the past seven days (as of July 29, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (30Jul2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 6. Observed cumulative precipitation across the Canadian prairies the past 30 days (as of July 29, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (30Jul2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209
Figure 7. Observed cumulative precipitation across the Canadian prairies for the growing season (as of July 29, 2020).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (30Jul2020). Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true&reset=1588297059209

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Drought Watch Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch website, Environment Canada’s Historical Data website, or your provincial weather network.