Since the first week of May, we’ve seen an omega-blocking ridge form across the Pacific Northwest Territories, British Columbia. This has resulted in both higher-than-average temperatures and new records having been surpassed in places like Seattle and Portland, where consecutive 90s were observed over the past week. Furthermore, we’ve seen poor air quality with wildfires across Canadian provinces causing smoke to be trapped in the high-pressure dome. This has been done in the Pacific Northwest and northern Plains states where air quality warnings are still in effect.
Using steam imaging, we can see a general counter- (or clockwise) flow through Western Canada outlining our omega ridge. We will now see this ridge break to some extent and shift eastward bringing the risk of milder temperatures and near-record values for the Intermountain West and northern Plains.
Over the next few days, we should see the core of the ridge shift eastward toward Saskatchewan and Manitoba. This will shift the average temperature above eastward to the Northern Plains next week, as trough-type relief shifts into southern British Columbia and Washington bringing rain patterns and sub-zero temperatures. medium. Anywhere between 5 and 20 degrees above normal would be expected as the high pressure shifts eastward.
As we see it, the popular 80s and near 90s will move from Washington to the Montana, Dakotas and to Minnesota over the next week before the ridge breaks and we transition to a more regional pattern leading up to Memorial Day. Weekend where large-scale ripples begin to cover much of CONUS and broad above-average temperatures look likely.
About the author
Hello! My name is Armando Salvadore and I am a Mississippi State graduate with a Bachelor of Professional Meteorology and an Activity Meteorologist working in the Private Sector. Stay tuned if you like technical, exotic, and general weather tweets! Also big on long-range forecasting as well! Twitter: @KaptMands