Reverse trajectories (RT)
Wind trajectories have been monitored since April 1 this year. To date, winds have originated predominantly from the USA - Pacific Northwest (PNW). Overall results indicate that eastern locations on the prairies have had fewer of these winds than western locations (Figure 1). Over the last week (April 25- May 1, 2017), Lethbridge has had significantly more RT’s from the Pacific Northwest than either SK and MB sites (Figure 2).
|Figure 1. Summary of reverse trajectory wind data (PNW) for the prairies April 1-May 1, 2017.|
|Figure 2. Based on results for specific locations (Brandon, Saskatoon, Lethbridge), Lethbridge has had significantly more RT’s from the Pacific Northwest than SK and MB.|
Forward trajectories (FT)
Forward trajectories that were predicted to cross the prairies from the southern USA and Mexico have been limited so far. There were a few isolated days of winds from Santa Maria and Imperial Valley, CA. and from Mexicali, Mexico in mid-April.
Weather forecasts (7 day):
Grande Prairie: https://weather.gc.ca/city/pages/ab-31_metric_e.html