FXUS65 KBOI 022117 AFDBOI Area Forecast Discussion National Weather Service Boise ID 317 PM MDT Wed Jul 2 2025 .SHORT TERM...Tonight through Friday night...An upper-level shortwave trough has made its way into SE Oregon this afternoon. Thunderstorms are ongoing and forming across much of SE Oregon and parts of SW Idaho. Satellite reveals widespread cumulus development over the past two hours leading up to this as well as continued robust development. A Red Flag Warning remains in effect today for the likelihood of scattered lightning over much of eastern Oregon. In addition, an Heat Advisory is in effect for the Lower Treasure Valley of Oregon through tonight. Although temperatures will be a few degrees less hot compared to yesterday, the relative humidity will be higher, resulting in similar heat risk. Mesoscale models have decreased coverage over the past few runs, however, forecaster confidence has remained. The primary threats are damaging wind gusts, with gusts up to 40-50 kts possible, and small hail. DCAPE values of near 1300 J/kg are becoming widespread as 20Z, with local maxima of 1600 J/kg or greater being forecast. With these values, strong wind gusts are certainly possible if storms can capitalize on the CAPE values near 500 J/kg. Thursday morning into afternoon will be quiet before a strong upper-level shortwave trough moves into the area evening/overnight Thursday into Friday. Precipitation chances will increase as this moves in, with moisture values and temperatures sufficient to threaten thunderstorms again for both days. DCAPE values and temperatures will be lower on both days. The threats are mainly focused close to the NV border Thursday evening, increasing to become widespread Friday.Our current thinking is that we may see significant storms late Thursday night extending right on into Friday morning and through the day Friday. The trough is notably stronger than the one we will see today, but thermodynamic parameters will be weaker. .LONG TERM...Saturday through Wednesday...As the upper-level trough that impacted the region Friday moves east, another upper-level trough will stall out over the coast of California over the long term period. As this happens, a strong upper-level ridge will build in over the Desert Southwest and Great Basin. Dry southwesterly flow will envelop SE Oregon and SW Idaho. This will lead to a steady increase in temperatures Saturday through Wednesday. Disagreement among long range models is high on how the upper-level low off the coast of California will progress, whether it rides the ridge or otherwise, however, the ridging is well agreed upon. Temperatures will begin around 5 degrees below normal Saturday, near normal Sunday, 5 degrees above normal Monday, and around 10 degrees above normal Tuesday and Wednesday. Lower elevation locations may experience 100 degrees starting Monday (10-20% chance), with higher chances of reaching 100 degrees Tuesday and Wednesday (30-60% chance). && .AVIATION...Mainly VFR. Isolated showers and thunderstorms to continue through 06Z this evening across SE Oregon and the higher terrain of SW Idaho with gusts to 50 kt. Scattered showers and thunderstorms across SE Oregon and the central ID mountains on Wednesday, and isolated elsewhere across southern ID. High density altitude due to heat. Surface winds: WNW 10-20 kt, becoming variable less than 10 kt overnight. Winds aloft at 10kft MSL: variable 5-15 kt. KBOI...VFR. High density altitude due to heat. Isolated showers and thunderstorms possible this evening and again tomorrow afternoon. Surface winds: WNW 8-12 kt. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...Red Flag Warning until midnight MDT /11 PM PDT/ tonight ORZ670-672>675. Red Flag Warning from 2 PM to 8 PM PDT Thursday ORZ670-672. Heat Advisory until 9 PM MDT /8 PM PDT/ this evening ORZ064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...CH LONG TERM....CH AVIATION.....SA