@ FXUS65 KBOI 200530 AFDBOI Area Forecast Discussion National Weather Service Boise ID 1130 PM MDT Tue May 19 2026 .UPDATE...Updated aviation discussion. && .KEY MESSAGES... - Mostly dry with temperatures warming through Friday. - Well above normal temperatures over Memorial Day Weekend. Gusty winds and a few mountain showers possible on Memorial Day. - Turning cooler early next week with gusty winds and increasing chance of precipitation starting Tuesday. && .SHORT TERM /Through Thursday Night/... Issued 157 PM MDT TUE MAY 19 2026 Our region will remain positioned on the western edge of upper level troughing through Thursday. While the focus of organized precipitation will remain to our east, daytime instability will support widespread cumulus buildups over the mountains as seen this afternoon. There's a slight chance that showers could develop from the cumulus field across e-central Oregon and w-central Idaho mtns each afternoon. Localized gusty winds will be possible from showers or more robust cumulus (with or w/o precipitation). Shower chances briefly increase to 15-25% in the w-central Idaho mtns and s-central Idaho zones Wednesday night in response to a passing shortwave trough. Otherwise it's dry and temperatures are on the way up, leaving behind any frost/freeze concerns for the Snake Plain. By Thursday high temperatures will be several degrees above normal. && .LONG TERM /Friday through Tuesday/... Issued 157 PM MDT TUE MAY 19 2026 A ridge of high pressure will build over the Western US by the end of this week, bringing generally clear, warm and dry conditions to the region through Monday. Temperatures will be about 10-15 degrees above normal. The ridge will reach peak strength on Sunday, with high temperatures near 90F in the Treasure Valley. By Monday, models indicate that an upper level low moving into the Pacific Northwest will begin to increase chances for precipitation. The upper level trough will move inland on Tuesday, with about half of the models showing that the trough will evolve into a closed low over the Pacific NW by Tuesday or Wednesday. In either scenario, temperatures will cool down 10-20 degrees by Tuesday increasing winds and chance of showers and thunderstorms (20-30% chance). && .AVIATION /06Z Wednesday through Thursday/... Issued 1127 PM MDT TUE MAY 19 2026 VFR. Mid and high clouds on the increase into Wednesday afternoon with WNW winds increasing as well. Showers possible over central Idaho after 20Z. Surface winds less than 10 kt, becoming WNW 10-20 kt with higher gusts after 20Z. Winds aloft at 10kft N 20-30 kt. KBOI...VFR with some mid/high clouds. Surface winds SE less than 10 kt, becoming WNW 10-20 kt after 20Z. && .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 AVIATION.....MC SHORT TERM...DG LONG TERM....JB