Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
739 FXUS65 KBOI 260246 AFDBOI Area Forecast Discussion National Weather Service Boise ID 846 PM MDT Fri Apr 25 2025 .DISCUSSION...Weak convection is still occurring around the area, with a few heavier showers over the Boise Mountains and near the Owyhee Mountains. Earlier this evening, we had several strong rain showers/weak thunderstorms and a gust front over southern Malheur County, Southwest Highlands, and the Magic Valley. Winds as high as 58 mph were recorded with the stronger storms, and small hail was observed, mainly near the NV border. Rain showers will continue through the evening mainly over the northern portions of our CWA. A few thunderstorms will linger tonight, mainly near the NV border. The strong upper level low will swing south of us tomorrow and then up into our region by Sunday, continuing to advect moisture over our region through the weekend. Precipitation chances will continue through Monday morning, with cooler temperatures anticipated Sunday. No updates to the forecast. && .AVIATION...Mostly VFR. Scattered to isolated showers tonight in a line northwest of KBNO-KBOI and near NV border, redeveloping tomorrow afternoon mainly near KREO-KBNO. Brief MVFR conditions possible in showers/thunderstorms. Low confidence in morning valley fog, with low ceilings and mountain obscuration in Eastern Oregon. Surface winds: variable less than 10 kt through overnight, becoming NW-NE 10-15 kt tomorrow afternoon. Winds aloft at 10kft: S-SW 15-30 kt. .KBOI... VFR. Low patchy stratus near the foothills tomorrow morning, becoming dry with mid level clouds through the day. Surface winds variable less than 8 kt overnight, becoming N-NW 5-10 kt by Sun/00Z. .SUNDAY OUTLOOK... Mainly VFR. Active weather through the weekend, with isolated afternoon showers and thunderstorms throughout the area. Showers/thunderstorms may result in areas of MVFR, mountain obscuration, and gusty outflows. Winds mostly NW-NE 10-20 kt with gusts to 30 kt by Sunday afternoon. && .PREV DISCUSSION... SHORT TERM...Tonight through Sunday night...Thunderstorms began shortly after noon MDT in southern Owyhee County. Hi-res models show them increasing and moving north through the evening, then collecting in eastern Oregon overnight. NamNest, in particular, shows a line of storms around 6 PM MDT extending through Rome/OR-Mountain Home-Glenns Ferry-Fairfield, shifting north. This line is forecast to pass through the Boise metro around 7 PM MDT. Expect wind gusts to 50 mph and brief heavy rain. In the NamNest model the line is narrow and should pass through any location in less than one hour. Pcpn should continue through the night in eastern Oregon. QPF has increased tonight compared to previous model runs, and nearly all of them have at least .10 inch tonight. After a break Saturday, showers and thunderstorms should increase Sunday as the main Pacific upper low tracks inland and across northern Nevada. At the same time, an upper through will be tracking eastward along the Canadian border, with the Nevada low and the northern trough roughly in phase with each other. Showers and thunderstorms should become more numerous Sunday in our Idaho zones as the upper low and trough pass by. Total QPF tonight through Sunday has increased to .50 to 1.00 inch near the Nevada border, around 50 inch in the Boise Mountains and Camas Prairie, .20 to .30 inch in Harney and Malheur Counties, around .25 inch in the Snake Basin, and less than.20 inch in our northern-most zones, farthest from the Nevada low. Daytime high temps this weekend will be slightly cooler than today`s highs, while nights will be mild due to extensive cloud cover. Northwest winds will increase to 15 to 25 mph Sunday in eastern Oregon, gradually working into western Idaho late Sunday. LONG TERM...Monday through Friday...The back end of the closed low is expected to continue pushing east through the early hours of Monday as a ridge builds in from the northwest, bringing warmer and drier conditions Monday. A weak shortwave trough will dig across the area Tuesday, steering a northwest flow that will cool valley daytime temperatures into the lower 60s. Precipitation chances sit at 20-60% on Tuesday, with most expected over higher elevations. A strong ridge will build in across the region from Wednesday to Friday, returning drier and warmer than normal conditions. Valley daytime temperatures are expected to climb into the lower to mid 70s Wednesday to Friday, with snow levels generally in the 6000-7000 ft range before rising to around 9000 ft on Friday. && .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 DISCUSSION...SA AVIATION.....SA SHORT TERM...LC LONG TERM....JY