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KEY MESSAGES

- A Lake Wind Advisory for Fort Peck Lake has been extended through Midnight Thursday Night.

- A Late season snowfall is expected Thursday through Friday night, which may begin as a wintry mix.

- The heaviest snowfall accumulations of 3 to 6 inches are expected over Dawson, Prairie, and Wibaux Counties, with 1 to 3 inches over remaining NE Montana.

DISCUSSION

WEATHER PATTERN OVERVIEW:

The first area of focus on the forecast is in the near term as east to southeast winds. While winds have diminished early this afternoon, they are expected to ramp back up this evening into tonight and then persist through Thursday evening. Despite the pause, to simplify messaged opted to just extend the Lake Wind Advisory for Fort Peck Lake through midnight Thursday night. Despite the duration, the strongest and most persistent breezy conditions will likely be Thursday and Thursday evening.

Thursday, attention focuses on a late season winter type storm set to arrive across the region as low pressure tracks east out of Wyoming into the Dakotas. This places the CWA on the northern fringes of the storm track, close enough however for accumulating snow. Currently, the NBM shows support for 3 to 6 inches across Prairie, Dawson, and Wibaux Counties where a Winter Storm Watch remains in effect. Elsewhere, a broad 1 to 3 inches of snowfall appear most likely. For the 2 inch threshold, there exists a roughly 50 to 80 percent probability of at least 2" of snow by Friday night across the Watch area with a 20 to 40 percent elsewhere across NE Montana. For the 6 inch threshold, there exists a 30 to 50 percent chance across Wibaux County, and around a 20 percent probability over the remaining Watch counties, again through Friday night.

Temperatures may be mild enough for a mix of rain and snow on Thursday before switchover to all snow occurs Thursday night and Friday, with snow diminishing Friday night. Warm ground, high April sun angle, and precipitation type all represent uncertainty. Impacts could range from wet, slushy, or snow covered roads, reduced visibility, and stress to newborn livestock.

Ensembles show cooler and drier conditions behind the departing system this weekend before a return to milder temperatures early next week as the next upper level ridge pattern across the Pacific shore translates east over the Northern Rockies.

FORECAST CONFIDENCE & DEVIATIONS:

The main deviation included blending in a mix of NBM90 and NBM to nudge near term winds upward in line with recent observations and near term expectations. Meanwhile, pops were also massaged for collaboration ahead of the upcoming storm system. Confidence is high on a rain/snow mix changing to snow Thursday into Thursday night, winding down Friday night. Confidence is materially lower on snowfall amounts given precipitation type issues, as well as mild ground temperatures and/or a high april sun angle. Snowfall will have a tendency to accumulate more effectively at night, on grassy or colder more elevated surfaces such as car tops (or complex terrain), or on roads where intensity increases.

There is growing confidence an upper ridge will move in this weekend behind the trough.

AVIATION

LAST UPDATE: Wednesday April 1, 2026 at 1945Z

FLIGHT CATEGORY: VFR - MVFR today, VFR - MVFR - IFR tonight.

DISCUSSION: Expect VFR initially, but clouds will increase tonight and Thursday with the next approaching low pressure system. MVFR to IFR ceilings are likely tonight or Thursday with reduced visibility at times Thursday into Thursday night with rain and sow mix changing to snow.

WIND: East to SE 10 to 20 knots with occasional gusts to 25 kts through Thursday night.

GGW WATCHES/WARNINGS/ADVISORIES

Lake Wind Advisory until midnight MDT Thursday night for Central and Southeast Phillips-Central and Southern Valley-Garfield- McCone-Petroleum.

Winter Storm Watch from Thursday evening through late Friday night for Dawson-Prairie-Wibaux.