Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
226 FXUS65 KBOI 030257 AFDBOI Area Forecast Discussion National Weather Service Boise ID 857 PM MDT Tue Jul 2 2024 .DISCUSSION...Warm and dry conditions will continue this evening, with just a few cumulus clouds over the West Central Mountains. Northwesterly flow will persist through Wednesday, keeping temperatures slightly below normal. A weak shortwave passing to the northeast will tighten the pressure gradient enough to bring stronger winds across south-central Idaho on Wednesday afternoon. Low humidity (10 to 15 percent) combined with wind gusts up to 40 MPH will create favorable fire weather conditions, with a 20-40% chance of gusts exceeding 40 MPH. Later this week into early next week, a significant shift towards a large upper-level ridge over the region is heavily favored by the available guidance. Confidence is high for a period of hot temperatures, with highs exceeding 100 degrees for several days. The hottest days of the year are expected between Sunday (7/7) and next Tuesday (7/9). No updates are needed at this time. && .AVIATION...VFR. High density altitude will become a factor by the weekend into much of next week. Surface winds: N-NW 5-15 kt with gusts to 20 kt. West winds gusting to 25-35 kt after 03/15Z at KTWF/KJER. Winds aloft at 10kft MSL: W-NW 15-30 kt. KBOI...VFR with clear skies. Surface winds: NW 7-11 kt becoming NW 11-13 kt with gusts to 25 kt possible after 03/17Z. && .PREV DISCUSSION... SHORT TERM...Tonight through Thursday night...Forecast still shows dry northwest flow dominating through Thursday night. As a result, temperatures stay a couple degrees below normal Wednesday and warm to normal on Thursday as a ridge begins to build further west. Skies remain mostly sunny with no chance of precipitation. Afternoon winds on Wednesday will be breezy as a shortwave trough passes to our north, enhancing the surface pressure gradient. Gusts that afternoon will be 30-40 mph in parts of the Snake Plain including and to the east of Mountain Home, Fairfield, and Twin Falls. The dry flow bring afternoon RHs to the teens and single digits. While fuels aren`t quite critical in these areas yet, a Red Flag Warning was issued for Wednesday afternoon/evening in coordination with related agencies. While the winds on the 4th of July are well below Red Flag criteria, it`s still worth keeping caution in mind as the very dry conditions continue. LONG TERM...Friday through Tuesday...The focus of the long term remains on the development of a strong upper ridge over the western CONUS. The warming continues until early next week, when the ridge axis moves overhead and should hold temperatures fairly steady. There`s a 20-40% chance of 100+ degrees on Friday in the lower Snake Plain and parts of SE Oregon while Saturday onwards 100+ degrees becomes much more likely. Afternoon high temps will be 10-15 degrees above normal, and morning lows 5-10 degrees above normal. The slightly lower morning low anomaly is due to very dry conditions through the long term, and with some afternoon breeziness possible we`re keeping an eye on the fire weather set up. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Red Flag Warning from noon to 9 PM MDT Wednesday IDZ424-426. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...JDS AVIATION.....SA SHORT TERM...JM LONG TERM....JM