Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
436 FXUS65 KBOI 161557 AFDBOI Area Forecast Discussion National Weather Service Boise ID 957 AM MDT Sun Jun 16 2024 .DISCUSSION...An upper trough approaching from the northwest will bring increasing clouds today, especially to southeast Oregon and central Idaho. There is less than a 20 percent chance that showers reach Baker County this afternoon along the leading edge of the trough. High temps will be 5 to 10 degrees below normal along with generally light winds. No updates. && .AVIATION...VFR and mostly clear until late this afternoon/evening. Rain/snow showers move from NW to SE after Sun/22Z through Monday morning. Greater than 30% chance of precipitation in SE OR and the west-central ID mtns, while the Snake Plain remains mostly less than 30%. Snow levels 5000-6000 ft MSL. Areas of MVFR/IFR conditions developing and mountains becoming obscured as precipitation expands. Surface winds: W-NW 5-15 kt this morning, increasing to 10-20 kt in the afternoon. Gusts 20-30 kt tonight as a cold front moves through. Winds aloft at 10kft MSL: SW 15-25 kt, becoming W-NW 15-30 kt after Mon/09Z. KBOI...VFR and mostly clear today. Rain showers and overcast clouds developing between Mon/06Z through Mon/18Z. 10-20% chance of rain at the terminal during this period. Surface winds: NW 6-12 kt, with gusts 20-25 kt developing this evening. && .PREV DISCUSSION... SHORT TERM...Today through Tuesday night...An unseasonably cool upper level trough will remain over the Pacific NW Sunday and Monday before moving eastward. This will bring breezy west- northwest winds during the afternoons each day through Monday. Temperatures will also be 10-20 degrees below normal through Monday. The bulk of the moisture will be north of the area today, with scattered showers developing north of a line from Burns, OR to Boise late this afternoon and continuing overnight into Monday. The main trough moves overhead on Monday morning, with the coolest air aloft over the area. This will bring scattered showers and isolated thunderstorms during the afternoon, with light snow showers in the mountains above 5000-6000 feet. Minor snow accumulations above 5000 feet, but will quickly melt off once the sun rises and warms up the ground surface, due to the June sun angle. Monday will be the coldest day of the period, nearly 20 degrees below normal, and also windy, with northwest winds 20-30 mph and gusts to 45 mph. May need a wind advisory for the Upper Treasure and Magic Valley Monday afternoon once forecast confidence increases. The trough will move eastward on Tuesday, with drier and warmer conditions expected. Some lingering showers possible over the central ID mountains Tuesday. LONG TERM...Wednesday through Sunday...The upper flow throughout the long term remains mostly southwesterly, supporting a warming trend and drier conditions. Precipitation chances over parts of the West Central Mtns were reduced to <5% in this forecast as the upper flow is looking a little drier than previous model runs. Chances may bounce back in future forecasts if guidance returns to previous moisture levels. The upper flow is fairly weak, keeping winds mild. Sunday afternoon/evening will be breezy as a low passes to the north and the gradient in the flow increases. Temperatures warm from about normal on Wednesday to 10-15 degrees above normal by Saturday. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...BW AVIATION.....ST SHORT TERM...KA LONG TERM....JM