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.
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).
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.
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.
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).
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.