Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
845 FXUS65 KPIH 212000 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 200 PM MDT Fri Jun 21 2024 .SHORT TERM...Tonight through Sat night. Enough moisture, heating, and unstable air along the border with WY south of Palisades Reservoir to trigger some isolated thunderstorms and light rain showers during the early evening. Skies will clear until very early morning Sat when a mid-level layer of clouds moves through the areas south of Blackfoot`s latitude, thinning out during the early afternoon. The timing should allow central and eastern Idaho to escape Sat afternoon with no showers or thunderstorms. The strong sunshine will allow deep mixing and so gusty afternoon and evening wind should develop, mainly over the Arco Desert region, and nothing more than breezy conditions (10 to 20 mph gusts to 30 mph). But the main forecast issue is the heat. Strongest sunshine of the year will couple with the heated air mass coming in from the south and temperatures should soar into the lower and middle 90s for elevations in the Southern Hills less than 6000ft and the eastern Magic Valley. Farther north in the Snake River plain, afternon highs will still be in the 80s and lower 90s. The overnight lows on Sat night in the southern hills stay very warm, especially at the inversion top, where they will stay in the 60s, and even the low 70s. This is a small area, and after some discussion was not seen as extensive enough for any Heat Advisory or Excessive Heat Warning. The area of marginal threat of reaching Heat Advisory decreased as well for Sat, compared to previous forecasts. As of right now, the low temperatures, high temperatures, and the climatic temperatures have not produced the need for any headlines, although it is very close. Messick .LONG TERM...Sunday through Friday. Main impacts in the long term will be hot conditions and occasional breezy to windy conditions as well. Sunday will be the hottest day in the long term with highs in low elevations in the mid to upper 90s and mainly 80s in the mountains. Wind speeds of sustained 15 to 30 mph are expected in the upper snake river plain as well. Will see a slight cool down Monday of about 5 degrees with low elevations highs down to the upper 80s to lower 90s and mountains in the 70s and 80s. Breezy to windy conditions again in the Snake Plain with again winds 15 to 30 mph sustained. Temperatures will warm again through mid week with highs in low elevations well into the 90s again by Wednesday then the model blend is expecting a significant cool down Thursday into Friday but low confidence that far out as the blend by Friday has highs down into the 60s mountains and 70s low elevations. The chance for showers and thunderstorms returns mainly in the eastern highlands both Thursday and Friday. GK && .FIRE WEATHER... Main impact will be isolated thunderstorms early this evening in zones 411 and 413. Otherwise it will be dry Saturday through next Wednesday. Expect breezy to windy conditions Sunday through next week with general sustained winds in many areas in the 15 to 30 mph range and gusts into the 30s. It will also be very dry with minimum humidity in the 10 to 20 percent range through Wednesday. Highs will generally be in the 80s mountains and 90s valleys through Wednesday. Expect a bit of a cool down next Thursday and Friday with the potential for below normal temperatures by the end of next week, but low confidence at this point that far out. GK && .AVIATION... Widespread VFR conditions will continue with some mid and high level clouds this evening with mainly clear skies overnight into Saturday. Expect brunt of thunderstorms activity this evening to be south and east of all TAF sites with DIJ the only site where could see showers or even a thunderstorms vicinity. At present only have VCSH. Not expecting significant winds through Saturday. May increase to around 10 knots Saturday afternoon at all sites. GK && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$