textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Drying trend through Friday with building high pressure.

- Showers, thunderstorms, and cooler temperatures return this weekend, focusing along the divide, Lemhi County, and southwest Montana. - Monitoring trend for widespread precipitation by Wednesday and Thursday next week with a closed low pressure system.

A few showers and thunderstorms remain in northwest MT. A few of these showers will be capable of quickly precipitating 0.10 to 0.25 inch. These showers will diminish late afternoon as the forcing moves east.

Friday, transient high pressure brings near normal temperature and the potential for elevated fire weather concerns in southwest MT. As fast as atmospheric heights increase, the next trough pushes into the Pacific northwest. Afternoon winds will increase, especially in southwest MT. While most locations can expect west winds 15 to 25 mph, southwest MT will see gusts to 35 mph, with a 40 to 60 % chance of gusts up to 40 mph. The combination of minimum RHs in the 20s with winds 15 to 35 mph, leads to the elevated fire weather concerns, use caution with any open flames.

Saturday the trough pushes instability into our area along with slightly cooler temperatures. Expect a breezy afternoon, temperatures 5-10 degrees cooler, and isolated showers and thunderstorms. The drier conditions in southwest MT may allow for an isolated strong storm producing outflow gusts up to 45 mph.

Sunday and Monday, breezy conditions and an isolated thunderstorm remain in the forecast for southwest MT. Additionally, cooler temperatures could produce light snow in the mountains above 6000 feet Sunday morning. Sensitive vegetation may require protection both Sunday and Monday mornings due to frost as temperatures may lower into the low to mid 30s depending on cloud cover.

Virtually all models continue to demonstrate another trough affecting the northern Rockies mid next week. There remains many questions on the depth, strength, and speed of the trough passage. Currently, the National Blend of Models has widespread probabilities of 50 to 80% of receiving a 0.50" or more of precipitation.

AVIATION

West- northwest surface winds are expected this afternoon, with gusts reaching 15-20kts. Through 4/2400z, a few showers or thunderstorms will be possible in northwest MT in the vicinity of KGPI. Expect brief but rapid reduction in visibility in stronger showers.

MSO WATCHES/WARNINGS/ADVISORIES

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