Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
436 FXUS65 KMSO 190919 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 319 AM MDT Thu Sep 19 2024 .DISCUSSION...A mostly dry west to northwest flow will develop over the Northern Rockies for the rest of the week and weekend. A weak ripple in the flow Friday will aide in an increase in westerly winds during the afternoon, with a 60-70% probability for gusts reaching 20 mph throughout western Montana and north- central Idaho. Those probabilities lower to 30-40% for widespread gusts of 25 mph. Those planing to recreate on Flathead Lake Friday afternoon between 3PM and 9PM should keep that in mind. The increase in wind Friday will also help with drying of the atmosphere and with partial clearing skies during the overnight hours, there will be increasing probabilities for areas of frost both Saturday and Sunday mornings. Frost probabilities range from 30 to 50 percent for the more populated valleys of western Montana. As for north-central Idaho, those outside of the higher elevated valleys (Orofino, Kamiah, & Grangeville) the probability for frost is less than 10%. From Weippe to Pierce, the frost probability jumps up to 60 to 70 percent. Around 50 percent of the ensemble clusters depict a weak shortwave trough by Monday, that will bring a general 20 to 30 percent chance for showers. Temperatures will be seasonable to start the week, then warming back to the 70s and 80s with dry conditions by mid- week. && .AVIATION... Patchy fog is possible in the valleys this morning. Otherwise, VFR conditions will be common both today and Friday with afternoon gusts of 15-20 kts at terminal sites. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$