Reverse trajectories (RT)
Wind trajectories have been monitored since April 1 this year. This week there was an increase in the number of RT winds that crossed the prairies from the Pacific Northwest (PNW) of USA. In Alberta, Grande Prairie and Beiseker had a significant increase in the number of RT winds over this past week (Fig. 1 and 2). In addition to the PNW, there were three prairie locations (Selkirk MB, Unity SK and Olds AB) that had winds originating from California and Texas.
|Figure 1. Weekly cumulative counts of Reverse Trajectories (RT) from the Pacific Northwest (PNW) from May 3-9, 2017 (2017 Olfert et al.).|
|Figure 2. Total number of RT winds from the Pacific Northwest from April 1-May 9, 2017.|
Forward trajectories (FT)
Similar to Reverse Trajectories, most of the model output of Forward Trajectories (FT) have originated from the Pacific Northwest (PNW). However, a few winds have been forecasted to cross the prairies from the southern USA since April 1, 2017 (Fig. 3).
|Figure 3. Source destinations and number of FT winds originating from the USA between April 1-May 9, 2017.|
Weather forecasts (7 day):
Grande Prairie: https://weather.gc.ca/city/pages/ab-31_metric_e.html