Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
885 FXUS65 KMSO 251851 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1251 PM MDT Wed Sep 25 2024 .DISCUSSION...The main impact for late this afternoon and evening will be the potential of localized strong wind gusts over 50 mph associated with thunderstorms, mainly north of a line from Orofino to Essex. Even though instability is marginal, deep-layer shear is strong (50 kts) allowing for the potential of a strong to severe thunderstorm or two. The higher probabilities for thunderstorms stretch from Lookout Pass to the Flathead Valley to Glacier NP from 6-10pm MDT. Otherwise, general gusty winds of 20-35 mph and scattered showers will be common with and behind a cold front this evening, especially from I-90 northward. Behind the front, daytime temperatures will cool back to more seasonable levels on Thursday with breezy westerly winds. The ridge bumps back up slightly Friday and Saturday with valley temperatures back to 10-15 degrees above normal and dry conditions. Nearly all the ensemble guidance have a weak trough passing through Sunday, causing gusty westerly winds once again. At this point the trough doesn`t dig deep enough for much precipitation, just some light showers in Northwest Montana and along the Divide. Daytime temperatures do cool back to seasonable levels once again. There is also a 60-70% probability of frost in the lower valleys of western Montana Monday and Tuesday mornings. && .AVIATION...Ahead of a cold front, southwest wind gusts of 15-30 kts will be common. Mid-level moisture, deep-layer shear, and marginal instability will allow for the potential of a strong storm or two north of a line from Orofino to Essex. Strong winds over 45 kts and small hail are threats with storms from around 25/2300Z to 26/0500Z. General showers will fill in behind the front lasting into early Thursday with mountain obscurations, especially from I-90 northward. Much of Thursday will be cooler with breezy westerly winds continuing. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Wind Advisory from 4 PM this afternoon to 11 PM MDT this evening for Flathead/Mission Valleys...Kootenai/Cabinet Region... Lower Clark Fork Region...West Glacier Region. ID...Wind Advisory from 4 PM this afternoon to 7 PM PDT this evening for Northern Clearwater Mountains. && $$