textproduct: Glasgow

KEY MESSAGES

- A weak low pressure system is expected a slight chance of mixed precipitation Saturday night into Sunday night. Above normal temperatures look to continue through Monday.

- A change in the weather pattern is expected starting Tuesday with colder temperatures, accumulating snow, and gusty winds.

DISCUSSION

WEATHER PATTERN OVERVIEW: A zonal pattern over Montana will allow a weak low pressure system to move through southern Saskatchewan on Saturday night. There is currently a mix of rain and snow forecast along the Missouri River and areas to the north of there. There is very little accumulation expected with this activity. Weak ridging will help maintain mild conditions through Monday.

A strong upper trough is expected to push southward from British Columbia, and this will extend far enough eastward to aid in a low pressure system moving across the area. There is a decent amount of uncertainty with precipitation type due to a large temperature swing, but overall there appears to be at least a decent chance of most the area receiving a wetting rain occurring on Tuesday into Wednesday. Snow that falls will have a rather strong east wind associated with it, so there are challenging travel impacts expected in this time period, especially in the northeast part of the area. For now, the mean NBM probability suggests potential for around 3 to 6 inches of snow in Sheridan, Daniels, Roosevelt, and Valley Counties, with 1 to 4 inches of snow in all other locations.

The 00Z GFS Ensemble suggests the upper trough will remain over the region after Wednesday, and lingering precipitation chances are expected on Thursday and Friday. Temperatures are expected to be closer to average after Tuesday as well.

FORECAST CONFIDENCE & DEVIATIONS: Made deviations for Saturday afternoon winds by utilizing NBM 90, and increased PoPs for Saturday night through Sunday night.

There is low to moderate confidence in mixed precipitation occurring for portions of the area Saturday night into Sunday night.

There is high confidence in temperatures through Monday, with moderate confidence after this time.

There is high confidence in the wind forecast for Saturday.

There is moderate to high confidence on most of the area receiving one tenth of an inch of precipitation on Tuesday into Wednesday, but low confidence on the timing of the change in precipitation type.

AVIATION

LAST UPDATE: 0615Z

FLIGHT CAT RANGE: VFR - MVFR

DISCUSSION: VFR conditions will persist with high to mid clouds through 06Z Sunday. There is low to moderate (20 to 40 percent) confidence of a low pressure system bringing a wintry mix to KGGW, KOLF, and KSDY after 06Z Sunday.

WIND: Light west through 09Z, becoming light and variable, becoming west at 9 to 16 knots after 18Z.

GGW WATCHES/WARNINGS/ADVISORIES

None.