


Area Forecast Discussion
Issued by NWS Boise, ID
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Issued by NWS Boise, ID
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-- Discussion containing changed information from previous version are highlighted. --815 FXUS65 KBOI 131552 AFDBOI Area Forecast Discussion National Weather Service Boise ID 952 AM MDT Sun Jul 13 2025 .DISCUSSION...-- Changed Discussion --Some minor updates made to the forecast this morning. Based on observations from yesterday, and in collaboration with neighboring offices, have opted to lower the forecast relative humidities for today through tomorrow. With minimum RHs for the day now forecasted to generally be between 10-15% for lower elevations and 20-30% across higher terrain. A new (as of yesterday evening) wildfire start in central Oregon is leading to more hazy skies this morning across southeastern Oregon and eventually spreading to far Southern Idaho this afternoon. Otherwise, aside from cumulus development over the central Idaho mountains, clear skies are expected throughout southwest Idaho. Aside from that, the current forecast looks to be on track with temperatures climbing to around 100 degrees throughout the lower elevations. Models continue to show Pacific moisture making into central Oregon, but not quite making it into Harney county. This should limit any isolated shower/thunder development to central Oregon, with the chance of anything making it into Harney county <15%. Mid-level clouds will increase in southern Oregon this afternoon.-- End Changed Discussion --&& .AVIATION...-- Changed Discussion --VFR. Localized smoke near wildfires. Fire in Crook County, OR may produce smoke near KBNO. High density altitude during afternoon hours due to hot temperatures. Surface winds: NW 5-15 kt with gusts 15-25 kt this afternoon. Winds aloft at 10kft MSL: NW 5- 15 kt. KBOI...VFR. High density altitude during afternoon hours due to hot temperatures. Surface winds: light and variable this morning, becoming NW 7-12 kt with gusts to 20 kt this afternoon.-- End Changed Discussion --&& .PREV DISCUSSION...-- Changed Discussion --SHORT TERM...Today through Tuesday night...The next couple of days are hot as our region remains on the northern edge of the Desert SW heat dome. Sites in the Treasure Valley and lower basins in SE Oregon could touch 100 degrees, with the Lower Treasure Valley seeing highs of 100 to 104. The Heat Advisory remains in place due to the combination of daytime heat and warm overnight low temperatures providing limited relief. Elevated moisture along the Sierra Crest yesterday, will expand into s-central Oregon today increasing afternoon cloud cover and the possibility of a shower or thunderstorm sneaking into southern Harney County. The w-central Idaho mtns will also see cumulus development this afternoon as a weak upper wave riding the ridge tracks though the ID panhandle. Moisture increases along the northern NV border on Monday, bringing a 10-15% chance of high- based showers and thunderstorms. An upper trough entering the Pac NW Monday afternoon will push a dry cold front through the region Monday evening. While winds will already be NWly, speeds will pick up across SE Oregon, with gusts of 25 to 35 mph possible through the evening. The cold frontal passage returns temperatures to around normal on Tuesday and keeps breezy northwest winds in place. A slight chance of showers and thunderstorms returns to s-central Idaho Tuesday afternoon, otherwise the region remains dry. Any shower/storm development through Tuesday will see little rain and locally gusty winds. A new wildfire in e-central Oregon along with other local/regional wildfires will continue to add smoke/haze to the area. LONG TERM...Wednesday through Sunday...Northwest flow aloft will prevail on Wednesday, keeping temperatures near normal with dry conditions. Ensembles generally indicate a ridge rebuilding across the northern Great Basin on Thursday, then persisting through Sunday. Models favor troughing to our north through the period, keeping the center of the ridge and associated hotter temperatures to our south. Temperatures are expected to average around 5 degrees above normal Thursday through Sunday under this pattern. Models continue to indicate potential for monsoon moisture to rotate around the ridge into our area, but potential at any given time and location remains low (less than 15% chance). Therefore, left shower/thunderstorm mention out of the forecast through the period. Expect breezy afternoon winds under west to southwest flow aloft.-- End Changed Discussion --&& .BOI WATCHES/WARNINGS/ADVISORIES... ID...Heat Advisory from noon today to 9 PM MDT Monday IDZ012. OR...Heat Advisory from noon MDT /11 AM PDT/ today to 9 PM MDT /8 PM PDT/ Monday ORZ064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...NF AVIATION.....LC SHORT TERM...DG LONG TERM....ST