Valid 2026-09-09 12:00 UTC – 2026-09-15 12:00 UTC

Discussion

Upper troughing will transition into the Great Lakes on Day 3/Wednesday, allowing high pressure to temporarily build into the northern Great Basin. On Day 4/Thursday, a mid-level shortwave trough will descend into the northwestern U.S., promoting widespread dry and breezy conditions across the region and into the northern Plains. A surface low will strengthen across the Dakotas as the associated shortwave trough departs; meanwhile, west-southwesterly flow will overspread the northwestern CONUS on Day 5/Friday. Ensembles are in general agreement for an upper-level low to traverse the Pacific Northwest and Northern Rockies this weekend. This pattern may provide broader precipitation chances and much cooler temperatures, thus subduing fire weather concerns across most of the northwestern/northern CONUS.

A dry airmass and strong westerly winds will expand across the northern Great Basin into the northern Plains on Day 4/Thursday. While such meteorological conditions would typically enhance fire weather concerns, the overlap of critical RH/winds is displaced from drier fuels. However, should these conditions expand over a more receptive fuelscape (particularly eastern Wyoming and western South Dakota), critical probabilities may be warranted in future outlook cycles. A southward progressing cold front may bring much cooler temperatures to the High Plains to end the work-week, though strong winds and low RH along/ahead of the front could revitalize fire concerns where fuels remain receptive.

Elizalde-Garcia · 09/07/2026