Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
115 FXUS65 KGGW 110808 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 208 AM MDT Sat May 11 2024 .DISCUSSION... KEY MESSAGES: - Warmer temperatures that will be above normal are expected through Monday. - There will be frequent chances for showers and thunderstorms beginning tonight and continuing for the next several days. WEATHER PATTERN OVERVIEW: An upper level ridge weakens today as it moves south. Surface high pressure remains over the area today with a warm and dry weather. Highs will be in the lower 80s in many areas. A shortwave trough on NW flow aloft moves through the area tonight and Sunday with a chance of showers and thunderstorms with a weak cold front that will bring slightly cooler temperatures on Sunday. Temperatures rebound on Monday ahead of a stronger shortwave trough, with a cold front that will move through the forecast area Monday afternoon and night. Models and ensembles are pointing towards enough instability for a few thunderstorms with this system. NBM has a 15-35 percent probability of a thunderstorm Monday afternoon and night at this point and a 30 to 60 percent chance of measurable precipitation. Temperatures are expected to be near normal Tuesday and beyond. Models and ensembles have upper trough lingering over the area through at least Wednesday with differences showing up in the pattern for late next week. CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST: High confidence exists on above average temperatures through Monday. The current NBM highs for today and Monday are at the lower end of the NBM possibilities (5-25%), so there is a good chance that the NBM is underforecasting the highs today and Monday. Raised highs for today and Monday a few degrees so that most locations are closer to the NBM 25%. Low confidence on timing of any showers and thunderstorms tonight and Sunday. Medium confidence on showers and thunderstorms Monday and Monday night. Low confidence on timing and showers and thunderstorms Tuesday and beyond. Expect, highly variable precipitation amounts next week. && .AVIATION... LAST UPDATED: 0800Z FLIGHT CONDITIONS: VFR DISCUSSION: High pressure will remain over the area today. There will be some mid and high clouds at times. A cold front moves through the area tonight with increasing mid level clouds and a chance of showers and thunderstorms that will continue into Sunday. WINDS: Southwest at 5 to 10 knots this morning becoming west to northwest 10 to 15 knots this afternoon and north to northeast 5 to 10 knots tonight. && .GGW WATCHES/WARNINGS/ADVISORIES... None. && $$ weather.gov/glasgow