textproduct: Glasgow

KEY MESSAGES

- Areas of storms and showers through about 3 AM Wednesday. Isolated severe storms are possible.

- Another round of showers and storms on Wednesday.

- Expect highs to begin reaching the 90s by the weekend.

DISCUSSION

WEATHER PATTERN OVERVIEW:

Tonight: A shortwave trough and sloped warm front have arrived. There is decent lightning occurring with these storms that will pass through overnight. A surface low will progress through the flow as well to bring some reasonable rain amounts. From now through Tuesday night, the base NBM indicates most of the area will see from 0.09 inches up to 1 inch of rain by 6 AM Wednesday.

Another shortwave trough is expected to move through the flow on Wednesday, and up to half an inch of rain is possible in thunderstorms. Then the heat starts its progression into the area. The latest GFS ensemble suggests temperatures will start reaching the 90s for high temperatures by the weekend. This is the time of year where heat usually starts building anyway, so it will be important to find some shade during peak heating.

FORECAST CONFIDENCE & DEVIATIONS: Made deviations to winds through 6 PM Tuesday to account for the Lake Wind Advisory that was issued for Fort Peck Lake.

There is high confidence in rain occurring through about 3 AM Wednesday, and then a break through the early afternoon, and then a round of showers and storms through Thursday morning.

There is moderate to high confidence in the Lake Wind Advisory that is in effect through 6 PM Tuesday and for rain totals through Wednesday night. There is low confidence in severe weather occurring through Thursday.

There is high confidence in high temperatures reaching the 90s for most locations starting this weekend.

AVIATION

LAST UPDATED: 0527Z

FLIGHT CATEGORY: VFR - IFR

DISCUSSION: Late evening showers and thunderstorms are arriving for KGDV and KGGW now. They will filter into KOLF and KSDY by 09Z as the low pressure system officially moves in. There is moderate to high confidence of MVFR conditions occurring from 14Z Tuesday through 6Z Wednesday, and low confidence in IFR in that period. Rain showers and isolated thunderstorms are part of the story, with heavy rain being possible at times.

WIND: East at 5 to 15 knots, increasing to 10 to 20 knots after 09Z.

GGW WATCHES/WARNINGS/ADVISORIES

Lake Wind Advisory until 6 PM MDT Tuesday for Central and Southeast Phillips-Central and Southern Valley-Garfield-McCone- Petroleum.

Flood Watch through late Tuesday night for Central and Southern Valley-Dawson-Garfield-McCone-Prairie-Richland-Western Roosevelt- Wibaux.