Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
966 FXUS65 KGGW 092237 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 337 PM MST Tue Dec 9 2025 .DISCUSSION... KEY MESSAGES: - Some lingering breezy to gusty winds are still possible this afternoon. - A wintry mix of rain, snow and freezing rain is expected early Wednesday morning through Thursday evening. - A strong winter storm with accumulation is possible Thursday evening through Saturday morning. WEATHER PATTERN OVERVIEW: The rainfall over cold road surfaces has all but finished this afternoon. There may still be a few sprinkes or flurries here and there, but the overall threat has diminished and the associated winter weather advisory has been cancelled. Model agreement continues to increase, allowing forecast confidence to reach better than average levels for the upcoming series of winter storm systems set to push through the region. A fluctuating front will become the focus for precipitation and the border between rain and snow over the next few days. Model data and expected environmental conditions continue to support the chances for freezing rain between those two. Given the wintry mix and possible ice accumulation, a new winter weather advisory has been issued for snow between 1 and 3 inches and ice between a trace and 0.05 inch. It should be noted that some model data was hinting at possibly greater amounts of ice accumulation. Next shift will need to look at this again for a possible headline upgrade. That mid-week weather system will almost seamlessly morph into the weekend snow storm. A winter storm watch has been issued for portions of northeast Montana where model data indicate significant accumulating snow could amount to 5 to 12 inches. More specific data will become available in the next few days, but generally expect less amounts in the northeast corner of the state and much higher amounts toward central Montana. The associated cold front temperatures will drop below zero degrees through this weekend winter storm. FORECAST CONFIDENCE & DEVIATIONS: Average to high confidence on the mixed precipitation occurring on Wednesday, along with fluctuating temperature boundaries. Average to high confidence on the accumulating heavy snow in the SW half of the forecast area between from Thursday through Saturday with lower confidence in the specific snow amounts for the NE corner zones. High confidence on the bitter cold temperatures Thursday night through Saturday night. && .AVIATION... LAST UPDATED: 2235Z, Tuesday afternoon 12/9 FLIGHT CAT: VFR, becoming IFR in snow toward the end of this TAF cycle. DISCUSSION: The flow pattern supports multiple rounds of wintry mix followed by breaks of partial clearing. Generally from the west tomorrow, snow will be followed by freezing rain, then rain. Later this week, a significant snow storm is possible with accumulations WIND: This afternoon/evening from the NW around 15 to 20 kts with a few stronger gusts. Tonight and overnight, from the NW around 4 to 10 kts, becoming light and variable or calm. Wednesday, from the E and SE around 10 to 15 kts. && .GGW WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 5 PM MST this afternoon for Central and Southeast Phillips-Central and Southern Valley-Daniels-Dawson- Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern Valley-Petroleum-Prairie-Richland-Sheridan-Southwest Phillips- Western Roosevelt-Wibaux. Winter Weather Advisory from 4 AM Wednesday to 8 PM MST Thursday for Central and Southeast Phillips-Central and Southern Valley- Daniels-Dawson-Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern Valley-Petroleum-Prairie-Richland-Sheridan- Southwest Phillips-Western Roosevelt-Wibaux. Winter Storm Watch from Thursday evening through Saturday morning for Central and Southeast Phillips-Central and Southern Valley-Dawson-Garfield-McCone-Northern Phillips-Petroleum- Prairie-Southwest Phillips. && $$ weather.gov/glasgow