Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
119 FXUS65 KGGW 142139 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 239 PM MST Thu Nov 14 2024 .DISCUSSION... KEY MESSAGES: 1) Dry weather and above normal temperatures will continue on Friday. 2) A cold front will arrive Friday night with a mix of rain and snow through Saturday. Highest confidence for accumulating snow is over higher terrain of the Little Rockies and Big Sheeps. WEATHER PATTERN OVERVIEW: Gusty winds this afternoon continue and so will continue with the Lake Wind Advisory for Fort Peck Lake through 5PM. Mild and dry weather will continue on Friday before the next cold front approaches. Rain and snow mix are expected initially, which has support from high res model guidance coming in and is in line with expected thermal profiles. Given low temperatures in the upper 20s and low 30s, a flip to snow is expected for most places on Saturday. Ensembles show ridging returning late in the weekend before the next trough appears early next week. FORECAST CONFIDENCE & DEVIATIONS: A blend with NBM90 was used in the short term given the observations and Lake Wind Advisory in effect. Broad consensus is building for a general 0.10" to 0.25" QPF event across NE Montana on Friday night and Saturday, though there continues to be wide spread among ensemble members in expected snowfall amount. Given precipitation type issues and marginally supportive temperatures for snow, confidence will likely remain lower than average going into the event. That being said, the NBM shows a 48 hour 50 percent probability of at least 2 inches of snowfall through Saturday across complex terrain areas like the Little Rockies and the Big Sheep Mountains. About a 1 in 3 chance for 2 inches of snow is currently indicated for the eastern zones. Thus, an advisory level event cannot be ruled out here, but greater confidence exists over higher terrain and further north and east where thermal profiles will more likely be supportive. Lower elevations will need to be monitored should the guidance come in colder. Given that it is early in the season, it would not take much snowfall accumulation to create wider impact for the area. && .AVIATION... Mid and high clouds will pass over the region from time to time this afternoon and evening with mainly clear skies expected tonight. Thus, look for VFR conditions to persist. West to northwest winds will continue at 15 to 25 kts, gusting to 30 kts at times through 01Z, then becoming southwest at 5 to 10 kts this evening and light and variable overnight. && .GGW WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory until 5 PM MST this afternoon for Central and Southeast Phillips-Central and Southern Valley-Garfield-McCone- Petroleum. && $$ weather.gov/glasgow