Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
716 FXUS65 KGGW 260802 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 202 AM MDT Wed Jun 26 2024 .DISCUSSION... KEY MESSAGES: 1) Dry weather continues today with near normal temperatures. 2) A strong cold front will push through the region on Thursday with growing support for severe weather across NE Montana from Thursday morning through Thursday evening. 3) Cool weather expected Friday and Saturday with chances for showers and thunderstorms on Friday. WEATHER PATTERN OVERVIEW: Upper ridging will prevail over the area today with dry weather. Surface low develops over central Montana tonight and ridge axis moves east turning the flow aloft to the SW which will allow for a chance of showers and thunderstorms. An upper low moves in from the west on Thursday. The surface low moves east across eastern Montana during the day on Thursday along with a surface cold front. SE winds ahead of the cold front will bring dew points into the 60s east of Glasgow and Jordan on Thursday. The mean surface based CAPE over eastern portions of the CWA looks to reach 2000 J/KG or better by Thursday afternoon and evening while forecast soundings show 40-50 kts of 0-6 km shear present. This will all set the stage for the return of active severe weather across NE Montana, especially during afternoon and evening hours. large hail and damaging winds will be the main threats. Precipitable water reaches 1.5 inches along the ND border Thursday afternoon and evening which could lead to locally heavy rain. Upper low/trough will move across eastern Montana on Friday with more showers and thunderstorms possible especially in the north. It will be a cool day with highs in the 60s NW and lower 70s SE. An upper ridge moves into the area on Saturday with dry weather. Warmer temperatures are expected on Sunday ahead of a cold front Sunday night and Monday with an upper trough that will bring chances for showers and thunderstorms. FORECAST CONFIDENCE & DEVIATIONS: The forecast followed NBM most of the time. Expanded the area of severe thunderstorms during the day on Thursday and Thursday evening beyond what the NBM forecasted to better match the SPC forecast of slight risk of severe weather. Confidence of high that there will be thunderstorms on Thursday especially in the afternoon and evening. Confidence is low on rainfall amounts as a few miles will separate whether a location gets 0.1 inch or 1 inch or more rain. WPC has a slight risk of excessive rain in Sheridan County on Thursday which looks reasonable given the high precipitable water. && .AVIATION... LAST UPDATED: 0800Z FLIGHT CAT: Areas of MVFR this morning. Otherwise VFR. DISCUSSION: There are MVFR level low clouds along the MT/SK border at 08z that area drifting south and dissipating before they reach any TAF site. A few of these clouds could reach either KGGW, KOLF or KSDY this morning before daytime heating dissipates these clouds. Otherwise, skies will be mostly clear today with some daytime cumulus this afternoon. Mid and high level clouds will move into the area tonight with a chance of showers and thunderstorms after 06z. WIND: North 5 to 10 knots early veering to the east this morning and SE 5 to 15 knots this afternoon. East winds 5 to 15 knots are expected tonight. && .GGW WATCHES/WARNINGS/ADVISORIES... None. && $$ weather.gov/glasgow