textproduct: Glasgow

KEY MESSAGES

- Isolated thunderstorms may form along the ND late this afternoon but severe chances are over the Dakotas today.

- Winds behind a cold front this afternoon will continue through Thursday, a Lake Wind Advisory has been extended to 9 PM Thursday evening.

- Seasonably cool temperatures with frequent chances for showers and thunderstorms look to continue this week.

DISCUSSION

WEATHER PATTERN OVERVIEW: A cold front will be bumping into a warm and humid airmass near the ND late this afternoon that will spark scattered thunderstorms. The threat of the storms turning severe will be brief in eastern Montana if they happen to form in Montana as they are expected to move northeast into ND. Any threat should be over with by early evening.

Then we turn to the affects of an upper trough that will be moving in from western Canada. The west winds this afternoon will help usher in cooler than normal air that will continue for the next several days. A Lake Wind Advisory has been extended till Thursday evening. It will feel more like April or May than June with these temperatures.

Rain chances will increase Wednesday night with a 700 mb trough moving southeast through the CWA followed by more wind in it's wake Thursday. A smaller chance of showers drop in Friday night/Saturday as an upper low drops south into the northern Rockies.

This low will reinforce the coolness but will be moisture starved.

FORECAST CONFIDENCE & DEVIATIONS: NBM was blended with with some of the CAMS for today to be more specific with the thunderstorms. Otherwise, used NBM through the forecast period.

Confidence then remains above average for seasonably cool and unsettled weather to continue this week given the overall handling of the trough. Confidence in exact timing, placement, and amount of precipitation remains low to moderate given the mesoscale detail still to be worked out a larger time scales.

TFJ

AVIATION

UPDATED: 1950Z/1:50 PM

FLIGHT CAT RANGE: VFR.

DISCUSSION: Aside from an isolated thunderstorm near KSDY late this afternoon, winds will be the greatest impact for aviation through Wednesday morning with cloud levels remaining at or above 10K ft AGL.

However, a system from the NW will bring in lower clouds late Wednesday with MVFR ceilings by evening and a better chance of showers as a system moves in from the NW. TFJ

GGW WATCHES/WARNINGS/ADVISORIES

Lake Wind Advisory until 9 PM MDT Thursday for Central and Southeast Phillips-Central and Southern Valley-Garfield-McCone- Petroleum.