Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
532 FXUS65 KPIH 232006 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 206 PM MDT Mon Sep 23 2024 .SHORT TERM...Tonight through Tuesday night. Satellite imagery shows broad swath of high clouds shifting south across East Idaho. This moisture continues to clear the region overnight while ridge of high pressure shifts east into Idaho. Ridge axis stays progressive while gradually amplifying through Tuesday morning, transitioning to southerly flow aloft. Breezy winds today diminish overnight and stay light under the ridge axis. Temperatures climb back to slightly above normal for Tuesday. DMH .LONG TERM...Wednesday through Next Sunday. Wednesday will be the warmest day of the week thanks to a combo of high pressure just to our southeast and southwesterly flow aloft bringing in warmer air. Highs will push into the mid 80s for most of the eastern Magic Valley and Snake Plain and the rest of our valley locations. The NBM even shows a 50 to 70 percent chance for highs to exceed 85 degrees in the eastern Magic Valley, but a less than 10 percent chance of reaching 90 degrees. Also on Wednesday, an upper level trough will begin to move into the West, which will tighten our pressure gradient enough to make it a bit breezy, though gusts will be around 20 to 25 mph that afternoon. With the ridging overhead weakened a bit for the second half of the week thanks to several systems passing well to our north in Canada, our temperatures will moderate a bit more with highs hanging out right around 80 degrees for Thursday, Friday, and Saturday. Afternoon wind gusts will remain in the 20 to 25 mph range, though Thursday gusts may be closer to 30 mph. On Sunday, a shortwave trough begins to move through the area which will help cool us down a few degrees into the mid 70s and bring a very small chance (about 10 percent) for a shower or storm up near the Island Park area. AMM && .AVIATION...VFR conditions are forecast through tonight. High cloud cover will continue to shift south out of East Idaho tonight. Breezy winds this afternoon diminish around sunset, and are expected to remain light overnight. DMH && .FIRE WEATHER...As one weak trough moves out of our area today, an upper level ridge will begin to build in behind it. Temperatures this afternoon remain comparable to the weekend, but ridging means we warm through the middle of the week with highs topping out in the mid 80s for much of the eastern Magic Valley and Snake Plain on Wednesday. The overall pattern will keep us dry for the week ahead, too, with the one small chance (less than 15 percent) for a shower or storm being late Wednesday in the western portion of Lemhi county. Minimum relative humidity will be generally in the 20 percent range through most of the week with it dropping into the upper teens out across parts of the Arco desert. The ridge is pushed eastward by a system moving into the PNW late Wednesday, but it changes little about our weather through the second half of the week other than dropping afternoon highs by just a few degrees. AMM && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$