Wind trajectories Related to Diamondback Moth (DBM) and Aster Leafhopper Introductions to the Canadian Prairies in 2015
BACKGROUND: Potential wind events capable of carrying insect pests from source areas in the USA can be identified by following trajectories for air parcels through time. High altitude air masses, originating from southern locations, frequently move northerly to Canadian destinations. Insect pest species such as Diamondback moth and Aster leafhoppers, traditionally unable to overwinter above the 49th parallel, can utilize these air masses in the spring to move north from Mexico and the United States (southern or Pacific northwest).
Wind trajectory data processing by AAFC-Saskatoon Staff began in April. Reverse Trajectories track air masses arriving across the prairies back to their point of origin. Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies.
Updated: May 4-5, 2015
1. Reverse trajectories
a. Pacific Northwest (PNW) – Between May 1-3, 2015, the predominate air mass source is continues to be the Pacific Northwest. Reverse trajectories model output for 10 prairie locations and indicated that winds arriving to the Canadian prairies originated from northwest USA between April 25-27, 2015.
2. Forward trajectories
Between may 1-3, 2015, there were five forward trajectories originating over Texas and California that are predicted to cross over the prairies over the 2-3 days. An example of forward trajectories for the Santa Maria CA example is below. Note how air masses are predicted to land in northeast Saskatchewan, northern Manitoba, and into Ontario.