Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
769 FXUS65 KBOI 221537 AFDBOI Area Forecast Discussion National Weather Service Boise ID 937 AM MDT Sat Mar 22 2025 .DISCUSSION...Bands of NW-SE oriented showers along a cold front will continue across central and southern portions of our area this morning as a cold front drifts slowly southward. The shower coverage will remain generally scattered and be confined to far southern areas as the front stalls this afternoon. Snow levels remain above valley floors, with local light snowfall amounts in the more persistent bands across the higher elevations. Winds have increased this morning, especially across s-central Idaho where there have been a few gusts in the 40-45 mph range. The winds will continue to ramp up through midday, then subside later in the afternoon. A Wind Advisory remains in effect for the Camas Prairie, Western Magic Valley, and southern Twin Falls County. No updates planned. && .AVIATION...Mainly VFR, except areas of MVFR/IFR conditions in the mountains with mountains obscured. Scattered to numerous showers this morning will decrease this afternoon with improving conditions. Snow levels around 4500-5500 feet MSL across the south and 2500-3500 feet MSL across the north. Surface winds: W-NW 10-15 kt with gusts to 25 kt, except 20-30 kt with gusts to 40 kt in the Magic Valley. Winds becoming variable 10 kt or less after sunset. Winds aloft at 10kft: W-NW 30-45 kt. KBOI...VFR under low to mid-level clouds. Scattered showers this morning should end by early this afternoon. Surface winds NW 10-15 kt with gusts 20-25 kt, subsiding early this evening. Sunday Outlook...Mainly VFR Sunday, except areas of MVFR/IFR conditions in the East-Central Oregon and West-Central Idaho Mountains as showers redevelop in these locations. Snow levels rising to 5000-7000 feet MSL by the afternoon. Surface winds SW- SE 5-15 kt with winds aloft at 10kft W-NW 20-35 kt. && .PREV DISCUSSION... SHORT TERM...Today through Monday night...Scattered showers continue this morning and afternoon, as a cold front stalls out over the area. Bands of heavy snow showers possible across the west central ID mountains this morning along the cold front, but the cold front will be a glancing blow to the rest of the area, with not much precipitation impact in the Snake Basin and areas south and west. The front will bring gusty west to northwest winds today, where a Wind Advisory remains in effect for the Magic Valley, Camas Prairie, and southern Twin Falls County for wind gusts up to 45 mph. Winds will subside after sunset this evening. The front stalls out and becomes stationary from Burns OR to Jerome ID this afternoon, keeping a threat of light showers over the area through midnight. Then a warm front lifts northward, with little precipitation and mainly will be focused over the west central ID mountains, Baker County mountains and areas north. This will be the start of a warming trend into Monday. Temperatures warm around 5-7 degrees each day on Sunday and Monday. LONG TERM...Tuesday through Saturday...A large amplitude ridge will continue to build in Tuesday over the western United States. Dry conditions can be expected Tuesday and Wednesday. Late afternoon Wednesday, temperatures will be reaching into the upper 60`s and 70`s in lower elevations with higher elevations seeing 40`s and 50`s. The probability of the Treasure Valley and Magic Valley temperatures exceeding 70F are over 50%. The probability of greater Mountainous areas experiencing greater than 45F temperatures is 40% or greater for all areas. Snow melt during Tuesday and Wednesday will rise from ~7,500 ft to near and, in some areas, over 9,000 ft. Combine all this together, and hydrologic impacts are of note; increases in river/stream/creek flows are expected as these temperatures accelerate snow melt from the lower and middle elevations. Late Wednesday into Thursday, a surface cyclone with an associated upper-level trough off the coast of the Pacific Northwest will infringe on the area. Of particular note, the GFS solution is quite different from the ECMWF and Canadian. The amplitude of the ridge in the GFS is weaker, as well as having the upper-level trough (with associated cold front & air mass change) weaker. This sets up a more southwesterly flow aloft compared to the ECMWF and Canadian which have much more southerly flow. This has important repercussions on shadowing from elevation and transport of moisture. QPF and PoP differences between the models show this well. Apart from all of that, winds will be strong late Thursday and slightly weaker but still strong on Friday. Too much uncertainty remains for Saturday with great disagreement between the GFS, ECMWF, and Canadian. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Wind Advisory until 6 PM MDT this evening IDZ016-028-030. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...BW AVIATION.....ST SHORT TERM...KA LONG TERM....CH