Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
647 FXUS65 KBOI 010929 AFDBOI Area Forecast Discussion National Weather Service Boise ID 329 AM MDT Sat Nov 1 2025 .SHORT TERM...Today through Monday night...The axis of an upper level ridge will move east of our area today as an upper trough begins to move into the Pacific Northwest. Southwest flow aloft will usher in a mild air mass, allowing high temperatures to increase by around 10 degrees from Friday. Warming will be aided by mostly sunny skies this afternoon. Winds will become locally breezy this afternoon, which will continue tonight into Sunday. The trough will move inland to our north tonight, bringing showers mainly north of a line from Rome OR to Boise to Atlanta ID. The best chance of showers will be across the far north near McCall and Baker City, where precipitation chances will range from 50 to 80%. Showers will taper off Sunday morning. Snow levels will be near 9-10kft tonight, lowering to 7-9kft Sunday morning. Precipitation amounts will be light, with only around a tenth or two of an inch expected in the northern mountains. Cooler air behind the trough will drop high temperatures by around 10 degrees on Sunday. On Monday, another trough near the coast will resume southwest flow across our area. Increasing moisture will bring a 20-50% chance of showers Monday afternoon through Monday night, with the highest chance across southeast Oregon and the west-central Idaho mountains. High temperatures will be similar in most areas to Sunday, except around 5 degrees of warming near the Nevada border. Breezy conditions will redevelop as the system approaches. .LONG TERM...Tuesday through Saturday...A plume of Pacific moisture residing over the region will generate showers through Tuesday morning and early afternoon, favoring higher elevations. Concurrently, southwest flow will begin to develop ahead of the next trough, amplifying a ridge over the forecast area by mid to late Tuesday and temporarily lowering precip chances. Warm frontal precip will then arrive from the southwest by Wednesday morning and spread into east Oregon and west-central Idaho. Temperatures are forecast to reach 5-10 degrees above normal during the day in this warm sector, despite thickening cloud cover and increasing precip chances. As the trough axis moves in from the west, a cold front will arrive by later Wednesday and support showers, gusty winds, and snow levels down to 6500-8000 feet MSL. Max temperatures are also expected to lower several degrees for Thursday behind the front. However, models are out of agreement on strength and moisture availability with this trough, reducing forecast confidence on shower coverage and temperatures. Current precip chances range from 45-70% for the north, and 20-45% for the south Wed into Thu. Thereafter, a slightly colder, more robust trough is expected late Thursday through late Friday, thanks to a prominent polar jet enhanced with ample Pacific moisture. Despite being a quick-hit, the GFS and ECMWF ensembles are favoring notable precip totals for the mountains while the Canadian ensembles suggest substantial weakening as the trough moves through the PacNW. Snow levels are forecast to lower to around 5500-6500 feet MSL, with temperatures remaining within a few degrees of normal for the end of the week. && .AVIATION...Generally VFR. Low confidence in patchy morning fog. Light rain showers and areas of mtn obscuration developing in NE Oregon & W-central Idaho (KBKE/KMYL vicinity) beginning late afternoon. Surface winds: variable up to 8 kt, then SW-SE 5-15 kt with 15-25 kt gusts this afternoon. Winds aloft at 10kft MSL: W-SW 15-30 kt. KBOI...VFR. Surface winds: SE 5-12 kt, afternoon gusts to 15-20 kt. Lowering ceilings with a 15% chance of light rain or sprinkles early Sunday. Sunday Outlook...Scattered light showers moving from NW to SE Sunday morning. Periods of low VFR/MVFR conditions and mountain obscuration in precip and low clouds. Snow levels lowering to 5000-8000 feet MSL, lowest on the back edge of precip. Surface winds: W-NW 5-15 kt. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...ST LONG TERM....SH AVIATION.....SH