textproduct: Glasgow

KEY MESSAGES

- A round of showers and thunderstorms is moving through the area now, and will eventually exit after 2 AM Friday. There is a low chance of severe weather in the far southeast.

- A weak disturbance will bring a moderate chance of showers and thunderstorms on Friday night. There is a decent chance of a lake wind product being needed for Fort Peck Lake during that time.

- A second wave of showers and thunderstorms is expected Saturday night into Sunday.

DISCUSSION

WEATHER PATTERN OVERVIEW: A shortwave trough is currently moving through central parts of the area, and it is bringing accumulating rain showers for some locations south of the Missouri River. There will be some high terrain influence behind this disturbance to bring scattered thunderstorms from the west this afternoon. Based on many different forms of model guidance, most of these storms are expected to be below severe limits. The 12Z max HREF wind gust has a severe gust in Prairie and Wibaux county this afternoon, but this has a 10 percent chance of occurring. A shortwave ridge will move in for tomorrow, followed by another weak disturbance Friday night. A strong trough is expected to build over the intermountain west on Saturday, and southwest flow into northeast Montana will bring a decent shot of severe thunderstorms in the afternoon. There is model disagreement on timing and location of storms, but any storm that develops will most likely be strong to severe. So far, the storm prediction center has large hail as a primary threat, especially in the eastern half of the area. Precipitable water values over 1 inch for Saturday brings heavy rain into the picture, so rises in streams will be monitored with the strongest storms.

Modest southwest upper flow for Sunday brings down the severe threat, as well as temperatures, so rain is still part of the story. This pattern is expected to continue through about mid June.

FORECAST CONFIDENCE & DEVIATIONS: The only NBM deviation was to increase afternoon winds for today and Friday.

There is high confidence in fire weather conditions remaining below critical on Friday.

There is moderate confidence in a Lake Wind Advisory being needed late Friday into Saturday.

There is HIGH confidence in showers and thunderstorms occurring through about 2 AM Friday, and in scattered severe thunderstorms occurring on Saturday.

There is HIGH confidence in temperatures through Saturday, with MODERATE confidence on temperatures from Sunday onward.

AVIATION

LAST UPDATED: 1822Z June 4th

FLIGHT CAT RANGE: VFR - MVFR, isolated IFR between 10Z and 14Z Friday.

DISCUSSION: A shortwave trough is moving through the area, and a band of showers and thunderstorms has developed as a result. There is high confidence this activity will affect TAF sites to bring brief MVFR conditions. This will eventually move east after around 8Z. With this precipitation, there will be enough surface moisture to allow a low probability of fog to exist between 10Z and 14Z. A shortwave ridge will bring VFR conditions after that.

WIND: Variable at 6 to 11 knots, becoming light and variable after 2Z, becoming west southwest at 8 to 15 knots after 18Z Friday.

GGW WATCHES/WARNINGS/ADVISORIES

None.