Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
457 FXUS65 KPIH 252002 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 202 PM MDT Tue Jun 25 2024 .SHORT TERM...Tonight through Wednesday night. SW flow aloft allowing for moisture to rotate NE into East Idaho from northern Nevada/California. NAM Nest model develops weak convection over the Southern Sawtooth region this evening, but signals are weak and there is little support from the remainder of the HREF components, so confidence is low. Better chances for light showers increase overnight as moisture deepens across the region. Convective intensity increases with isolated/scattered thunderstorms possible during the day Wednesday most areas. HREF components differ in timing and placement of thunderstorm coverage, but would expect the main limiting factor would be early cloud cover limiting some of the deeper instability potential. That said, some of the storms could be strong, though sub-severe, with 40-50mph gusts and small hail. The combination of increased moisture and precipitation development will help keep temps slightly cooler across the region for Wednesday, but highs will still range in the upper 80s to low 90s many low elevation areas. DMH .LONG TERM...Thursday through next Tuesday. An upper low will move onshore and track along the US/CA border with the associated trough and cold front shifting through Southeast Idaho on Thursday. The frontal passage will bring slightly cooler temperatures, advisory level winds to 55 mph across the Upper Snake Plain, and isolated showers and thunderstorms to extreme eastern Idaho. The Storm Prediction Center has included the eastern extent of the CWA in a general risk of thunder, with National Blend PoPs mostly ranging 20 to 40 percent. Daytime highs will return to within several degrees of normal for Thursday and Friday, but these relatively cooler temperatures will be short- lived. Models show high pressure rebounding on Saturday, with the NBM featuring about a ten degree increase in high temperatures between Friday and Saturday. The next approaching trough will bring another cold front through southern Idaho late Sunday which will provide slight chances for precipitation again and decrease temperatures to the low 80s and cooler early next week. Cropp && .AVIATION...VFR conditions along with mostly dry conditions forecast today. Cloud cover will continue to increase this afternoon and evening as a trough moves onshore. Isolated showers and thunderstorms could impact any terminal Wednesday, with the probability of thunder 50% to 70% at all terminals. Hi-resolution models show differences in precipitation timing, but the first band looks to shift northward by 15z with virga prior to that. Winds will continue to run breezy today and tomorrow, with SW sustained winds to around 20 kts and gusts to around 30 kts. Cropp && .FIRE WEATHER...Today will be the hottest day of the week before the high pressure ridge breaks down and a trough moves onshore. Widespread minimum humidities will range 10 to 20 percent today and winds will continue to be breezy today and tomorrow over the Snake Plain, with sustained winds to around 20 mph and gusts to around 35 mph. Isolated showers and thunderstorms could impact all of Southeast Idaho on Wednesday but will be less probable for South Central Idaho on Thursday. A cold front will result in stronger winds on Thursday, with gusts across Fire Weather Zone 410 expected to reach as high as 55 mph. Any thunderstorm outflow winds could also be capable of producing similar gusts. Temperatures will return to near normal for Thursday and Friday but will increase again for the weekend with high pressure returning on Saturday. Cropp && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$