textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- High pressure this week will result in warm temperatures and stagnant air

- Record-breaking daytime high temperatures on Thursday

- A pattern shift Feb 8-10 will bring increased precipitation chances

A ridge of high pressure will build over the Northern Rockies today and last through the remainder of the work week. Temperatures will remain well above normal. The forecast for Thursday shows record-breaking (or tying) daytime high temperatures for Missoula, Kalispell, and Butte. The lower Salmon River valley could see 70 degrees. One caveat to the high temperature forecast will be atmospheric stability and the ability for some valleys to hang onto colder air under inversions. Inversions will likely trap low stratus and fog in the valleys, particularly across northwest Montana and Clearwater County.

Looking ahead, ensemble clusters continue to suggest a pattern shift early next week. Current guidance indicates the ridge will break down as an upper-level trough digs along the West Coast. This transition would open the door for increased precipitation chances and a cooling trend, though confidence regarding the strength of this system remains low for both the timing and intensity of the trough.

AVIATION

GOES satellite imagery shows a ridge of high pressure building across the western US, with the Northern Rockies under northwesterly flow aloft. Waves of high clouds will continue to stream into the area from the northwest through tonight into Wednesday morning. Patchy areas of valley fog and low stratus will develop tonight given stable conditions under the ridge. This rings true for KGPI and KMSO, where probabilities of LIFR visibility associated with fog is 15-20% between 04/1000-1500Z.

MSO WATCHES/WARNINGS/ADVISORIES

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