textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Showers continue again today.

- Warmer, more mild weather for this weekend and early next week.

- Active weather returns mid next week.

The closed upper level low that brought much cooler temperatures to the region has moved east of the Continental Divide. It's left the region in slightly cyclonic, northwest flow with cold air aloft again today. That means when the sun comes up and warms things up at the surface, conditions will become unstable. The slightly cyclonic flow means the atmosphere at large won't do anything to suppress the convection that results, and the result is another round of showers today. Temperatures will trend about 8 degrees warmer than yesterday, so many valley locations that had snow showers yesterday will have rain showers or mixed rain and snow showers today and no accumulation on the roads is expected.

This evening a ridge builds in over the region and will last through early next week. This will cause mild weather and warmer temperatures. For Monday and Tuesday, the valleys of western Montana will reach into the 70s, with some locations like Missoula, the Bitterroot Valley, and Libby getting into the upper 70s. In central Idaho, many lower elevation locations will rise into the low 80s early next week.

Ensemble forecasts are in very good agreement for a cut-off low pressure system to move ashore in northern California and Oregon around Wednesday. That system will push some moisture and instability into our region, and we expect thunderstorms across the region mid to late next week. Once the system comes ashore, ensembles diverge on how it evolves, so there is little we can say about how long it will impact the region and how much of a cool down it will bring with it.

AVIATION

Expect another round of convection starting late this morning and lasting into the evening. Rising heights today as a ridge builds in will cap off the showers earlier in the evening than recent days, and any impacts at area terminals will be intermittent. A ridge starts to build tonight and we expect VFR conditions over the weekend and early next week.

MSO WATCHES/WARNINGS/ADVISORIES

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