textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Cold front continues pushing through today bringing cooler, showery and breezy conditions.

- Closed low impacting the region late Wednesday into Friday

The cold front is currently draped over north central Idaho into west central Montana. The front will continue to push southward throughout the day. The bulk of the precipitation will be associated with the front with a few scattered showers lingering behind the front. Breezy conditions are will be experienced across the region today with gusts up to 30 mph and higher gusts in the mountains. The biggest impact of these winds will be choppy conditions on Flathead lake.

The upper level flow will remain zonal (westerly) through Tuesday. The latest model runs are indicating that Lemhi county into southwest Montana will experience scattered showers during the afternoon.

By Wednesday, a trough is digging off the Pacific Northwest coast to eventually become a closed low. This will set up southwest flow into the northern Rockies region, and it will also bring more precipitation. By Thursday, the cold air associated with this low is over the region and the snow levels lower to around 4000 feet, causing a good Spring snow in many higher elevation valleys. Portions of the lower elevations of central Idaho, including Grangeville, have about a 50% chance of seeing accumulating snow while the median forecast for the mountains of central Idaho is closer to the 5 to 7 inch range. The valley snow in western Montana will be much more variable, from a trace to up to 6 inches in the in the higher elevation valleys (like Georgetown Lake). Further south in Lemhi County, ID, median snow forecasts by Thursday evening are around 1 inch of new snow with the 90th percentile forecast coming in at 2-3 inches. Whether in central Idaho, Lemhi County, or western Montana, the foothills and higher elevations around the valleys will pick up more snow, potentially 5-9 inches. But snow amounts in the terrain will be highly variable from location to location.

AVIATION

The band of precipitation associated with the cold front is currently draped over north central Idaho into west central Montana. The front will slowly push to the south throughout the day. The precipitation will transition from stratiform around the front to convective behind. Breezy conditions will develop this afternoon with all terminals expecting to have gusts of 20 to 30 knots by mid afternoon. The winds and convection will diminish during the evening hours.

MSO WATCHES/WARNINGS/ADVISORIES

MT...Winter Weather Advisory until 10 AM MDT this morning for West Glacier Region.

ID...None.