


Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
253 FXUS65 KGGW 192116 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 316 PM MDT Mon May 19 2025 .DISCUSSION... KEY MESSAGES: - Low pressure system will continue rain opportunities through Tuesday. - Opportunities for rain will return, mainly Thursday night into the weekend. WEATHER PATTERN OVERVIEW: Upper low that has brought the area some needed rainfall will remain centered over South Dakota til it moves east on Wednesday. A moisture surge from southeast to northwest will keep rain chances lingering over the NE zones longer with the chance of rainfall till about Tuesday night or Wednesday. The SW zones are expected to receive less than a tenth of an inch while northern and eastern zones should see close to a quarter of an inch, the most being in Sheridan county with close to a third of an inch. For tonight, clouds are expected to linger and could limit fog formation. I`ll leave inherited patchy fog as there is ample low level moisture in place. With light winds, fog is still possible if skies in places clear. On Tuesday, a weak ridge to our west will begin pushing in, proving some clearing and thus warmer temps. Temps should reach the 60s west but clouds and scattered showers over the east will keep things cool here. Temperatures will gradually warm into Thursday as sunshine will gradually modify the airmass. Look for highs Thursday to be in the 60s most places. A small but closed system enters the picture on Friday that could bring a wetting rain to parts of the CWA. This will also cool temps across the area back below normal. Afterwards, the models seem to be in disagreement so confidence on what happens is quite low. Steering currents look quite weak and the longwave models are trying to build an upper ridge over the western states while Friday`s disturbance may linger over eastern Montana. FORECAST CONFIDENCE & DEVIATIONS: Pretty much went with the NBM through the entire 7 day period. With the Aviation grids, sided with the HIRESarw for ceilings and Preferred Blend for visibilities. && .AVIATION... FLIGHT Category: MVFR, possible IFR MVFR ceilings will linger but could drop to IFR at KSDY and will remain at IFR at KGDV tonight. But confidence in these lower ceilings are moderate at best as observations have been higher than expected lately. WINDS: East/NE winds will decrease tonight. There is a slight chance of patchy fog late tonight but widespread conditions are not expected. TFJ && .GGW WATCHES/WARNINGS/ADVISORIES... None. && $$ weather.gov/glasgow