FXUS65 KBOI 141711 AFDBOI Area Forecast Discussion National Weather Service Boise ID 1011 AM MST Fri Feb 14 2025 .DISCUSSION...A complex broad upper low remains over the region today. Water vapor satellite imagery shows several smaller circulations embedded within the main low. One of the waves is tracking through SW Idaho this morning with an area of precipitation which is bringing moderate snow to the mountains. A second embedded feature over central Oregon will track through the region this afternoon through early evening bringing another round of rain/snow. Lower elevations across SE Oregon, the lower Treasure Valley and Weiser Basin will likely see snow or a wintry mix with precipitation that falls today where accumulations of up to an inch of snow are possible. In the Snake Plain, warmer air has edged into the Boise metro, with colder temperatures remaining entrenched west of roughly the Ada/Canyon County line for today. A similar situation in the western Magic Valley with the cold air remaining in place north of the Snake River this morning, but expect winds will be more successful at mixing out the cold air through the day. Have updated forecast for afternoon precip/snow amounts with this next wave. && .AVIATION...General improvement through the afternoon, but areas of LIFR-MVFR to continue, with mountains obscured near lingering showers. Warm front moving in from the southwest near KBNO-KJER-KTWF this afternoon, bringing rain to elevations below 5k ft and mountain snow showers through Sat/05Z. Patchy fog and low stratus in sheltered valleys today with clearing ceilings aloft. Surface winds: NW-NE 5-10 kt in valleys, becoming W-NW 5-15 kt with gusts to 25 kt by 20Z. Areas of low level wind shear through 18Z. Winds aloft at 10kft MSL: W-NW 20-30 kt. KBOI...VFR through 18Z, with a wintry mix this evening around 15/00Z. MVFR/IFR possible during precipitation and in patchy fog and low clouds with mountains obscured. Surface winds SE 10-15 kt, then W-NW 5-10 kt after 18Z. Weekend Outlook...Areas of fog/low ceilings Sat morning, then partial clearing Sat afternoon. Mountains obscured. Then, widespread MVFR to LIFR in snow/rain Sunday-Monday. Snow levels Sunday rising to around 3000-4500 ft MSL. && .PREV DISCUSSION... SHORT TERM...Today through Sunday night...An upper level trough remains over the region this morning, with several areas of showers over the Great Basin and central OR. This will keep a threat of rain and snow showers over the area today. Cold air remains trapped in the valleys this morning, with the exception of Boise itself, where temperatures have risen above freezing. Have kept the winter weather advisories and winter storm warnings going until 11am this morning, as slick roads remain and the commute will be difficult. The mountains will generally see 2 to 5 inches of additional snow accumulation today, with generally under an inch below 4000' MSL. Snow levels will rise 3500 to 4500' this afternoon, with the exception of the lower Treasure Valley, Baker County, northern Malheur County, and the Weiser River Basin. Cold air will remain trapped in these areas but slowly get eroded away today. The main cold front associated with this trough will move through the area late this afternoon, with snow levels falling back to the valley floors this evening as the precipitation ends. A dusting of snow is possible with the cold front. The system moves east on Saturday, with areas of fog developing on Saturday morning, partial clearing expected in the afternoon with cool temperatures. The next system quickly follows with snow developing Sunday morning lasting into Monday morning, light snow accumulations expected in the valleys with moderate accumulations possible in the mountains. LONG TERM...Monday through Friday...Monday morning, chances of precipitation lower throughout valley as a shortwave vacates our area to the east. Locations below 4000' MSL hold on a 40% to 50% chance of precipitation Monday morning, tapering off by midday. Mountain locations above 4000' MSL hold on to their precipitation chances throughout the day Monday, however the probabilities taper off by Tuesday. Wintery mix is the favored precipitation type for locations below 4000' MSL as snow levels initially at 2500' MSL to 2800' MSL, with the levels increasing as you move south and east. While these will rise throughout the day as temperatures warm, it will transition to rain as the dominate precipitation type. The Lower Treasure Valley will hold on to the wintery mix for most of the day thanks to some cold pooling. Locations above 4000' MSL favor snow throughout the entire day monday. Light precipitation is forecasted Monday, with the probability of seeing measurable precipitation ranging from 50% to 60% in valley locations. Mountain locations above 4000' MSL have a greater than 75% chance of seeing an additional two inches of snow Monday through Tuesday. Tuesday looks to be dry as a low amplitude ridge builds in behind the shortwave that provided the early week precipitation. Precipitation chances are raised Wednesday as model guidance indicates a shortwave ejecting through the larger scale trough. Although, as was the case yesterday, there is very little model agreement on the timing of this shortwave passage so exact timing can't be pinned down. The precipitation chances associated with this shortwave remain elevated through early Thursday morning. The dominant precipitation type of this system depends on the timing, if it arrives early Wednesday morning, snow would be favored across the entire area before transitioning to rain below 4000' MSL. If it arrives Wednesday afternoon, rain would be dominant below 4000' MSL. These details will be refined in future updates. Model guidance indicates a ridge building in following this shortwave passage, allowing for drier conditions across the majority of the area. Chances of precipitation remain slightly elevated (20% - 30%) in the West- Central Mountains due to some potential orographic lift of Pacific air. Temperatures in the long term show little daily variations staying around 5 degrees below normal. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory until 11 AM MST this morning IDZ011-013-015. Winter Storm Warning until 11 AM MST this morning IDZ012-014-016-028-029-033. OR...Winter Storm Warning until 11 AM MST /10 AM PST/ this morning ORZ061>064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...DG AVIATION.....SA SHORT TERM...KA LONG TERM....NF