Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
533 FXUS65 KBOI 032021 AFDBOI Area Forecast Discussion National Weather Service Boise ID 221 PM MDT Wed Jul 3 2024 .SHORT TERM...Tonight through Friday night...A Red Flag Warning is still out for parts of Southern Idaho, with at least one RAWS site reporting critical RH and wind so far. Temperatures warming through the short term. Near normal on Thursday increasing to 5 degrees above normal on Friday. Winds after Wednesday afternoon should become fairly typical. With the exception that gusts to 20-25 mph are possible Thursday afternoon between Mtn Home, Twin Falls, and Fairfield. In the same area, gusts to 25-35 mph are possible Friday afternoon. This could be a concerning fire weather set up with continued dry conditions, but not necessarily critical based on the current forecast. .LONG TERM...Saturday through Wednesday...Still high confidence in the development of a heat wave that will commence this weekend and persist into next week. An intense high pressure system near the west coast gradually moves eastward and the axis reaches our area by Monday. This will prolong and intensify our current very dry conditions, but the main hazard is the heat. Temperatures warm to near or over 100 degrees on Saturday and continue to gradually increase through the long term. By Tuesday our area warms to about 10-15 degrees above normal, which means highs in the range of 105-110 for our lower Snake Plain zones. This level of heat is flagged as mostly Major with some areas of extreme through our Heat-Risk product, meaning most people should take care to prepare for the heat, especially those sensitive to heat. The longevity of the heat is another major factor, with no definite end to heat in the forecast. Latest forecasts are challenging a few records, one of which is the most consecutive days of 105 or greater in Boise. The current record is 4 set in 2002, and the extended NBM indicates we could begin recording consecutive 105 days after Tuesday through the rest of next week. There will be some relief overnight as the lows stay around 70 in the Snake Plain and lows 60s to upper 50s for mountain valleys. Either way, the afternoon heat will be extreme. As a result, we are issuing an Excessive Heat Watch for most low elevation zones. The Watch for SE Oregon and the Lower Treasure Valley go into effect this Weekend, while the Watch for the rest of the Snake Plain/TV, far SW Idaho, and the Weiser Basin goes into effect on Monday. High elevation zones are very close to needing a product, but confidence isn`t quite high enough and the heat in these zones is still many days away. && .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 through this evening. Gusts to 25-35 kt through 04/03Z at KTWF/KJER. Becoming light and variable overnight. 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 through 04/03Z. Light winds overnight. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Excessive Heat Watch from Saturday afternoon through Wednesday afternoon IDZ012-029. Red Flag Warning until 9 PM MDT this evening IDZ424-426. Excessive Heat Watch from Monday afternoon through Wednesday afternoon IDZ014>016-030-033. OR...Excessive Heat Watch from Saturday afternoon through Wednesday afternoon ORZ061>064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise SHORT TERM...JM LONG TERM....JM AVIATION.....JR