textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Mild conditions most of the week.

- Change to a cooler, moister pattern this weekend.

- Snow potential coming late next weekend and early next week.

Warm and dry conditions continue, for now, Friday while temperatures remain 15 to 20 degrees above normal southerly winds increase announcing a trough digging to our west.

There remains significant uncertainty in how fast change comes to the Northern Rockies and how exactly that change manifests itself. One thing does seem certain, summer-like temperatures end. By Saturday, 75% of all model solutions have high temperatures 20 degrees cooler than Friday and 25% of solutions forecast a 30 degree change. Sunday's forecast suggests an additional 5 to 10 degrees of cooling. One other component that seems dialed in is breezy conditions pre cold front on Friday and then winds turning northeasterly Saturday as a backdoor cold front moves through the region.

What is still very much in question, how much precipitation ultimately falls, how low do snow levels lower, and how receptive a warm ground will be to accumulation in the mountains. Along the Continental Divide is the best location for both precipitation and simultaneously snow levels at or below pass level.

AVIATION

High pressure continues to dominate the air space above the Northern Rockies. Cold mornings, warm afternoons, with stable conditions is to be expected. Morning fog at KGPI is currently in the TAFs but may not be as problematic as the past few days.

MSO WATCHES/WARNINGS/ADVISORIES

MT...None. ID...None.