Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
936 FXUS65 KMSO 221842 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1242 PM MDT Sun Sep 22 2024 .DISCUSSION...A ridge of high pressure will build over the Northern Rockies to start the week, allowing for warm and dry conditions to prevail. Afternoon temperatures will be running 10-15 degrees above normal, with upper 70s/low 80s in western Montana and upper 80s in north-central Idaho. The ridge axis will shift east Wednesday as a shortwave trough approaches from the west. Temperatures will remain well above normal, but increasing west-southwest winds will occur, along with isolated showers and thunderstorms in the evening. Currently, there is a 50-60% probability for gusts exceeding 20 mph across the Northern Rockies. Gusts exceeding 30 mph will be possible with any convection, with northwest Montana having the highest probability at around 40%. A west-southwest flow will remain the predominate weather feature of the region through the rest of the week, until Friday when a Pacific cold front arrives with a strong jet stream sliding south out of British Columbia. Scattered showers, along with another breezy day will be the result. As it stands now, Friday is expected to be the windier day of the week, with a 40-50% probability for widespread 25+ mph gusts across western Montana. North-central Idaho will see much lighter winds during this period. 25 percent of ensemble cluster models are showing a change to a cool and wet pattern arriving by the end of next weekend or early next week. && .AVIATION...VFR conditions continue today under a westerly flow. A weak disturbance along the Canadian border has brought an increase in mid-level clouds across northwest Montana, that will eventually progress south and east across the Northern Rockies into the evening. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$