Our hot, Midwestern summer has been tempered over the past few days by a northerly flow, ushering cool Canadian air into the region. A high pressure ridge over the West Coast, which is bringing hot weather from the Southwest deserts to the Pacific Northwest, has produced a trough to its east, allowing the cool air to spill southward. This flow has been augmented by low pressure over the Northeast Coast; counterclockwise winds around the low have kept New England in its cool, wet pattern and, further west, are dragging Canadian air into the Heartland.
Yesterday, the trough was reinforced by another front out of Alberta, triggering severe weather across the Central Plains and heavy rain to its east and south. The broad sweep of Canadian air now stretches from the Rockies to the East Coast, bringing below average temperatures to much of the country. Unfortunately, it may not reach South Texas, where a severe drought persists.
Since the jet stream generally stays well to our north through July and August, such cool weather outbreaks and their associated storms more typically occur in the Dakotas and Great Lakes region. But we'll gladly accept the relief while it lasts!
