Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
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224 FXUS65 KPIH 240611 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 1211 AM MDT Fri Jul 24 2026 .KEY MESSAGES... - Surging Heat & Heat Advisory Friday: A building Four Corners ridge will push temperatures into the mid-to-upper 90s Friday through early next week. A Heat Advisory is in effect Friday for lower elevationsincluding the Snake Plain, Magic Valley, Arco Desert, Shoshone, and South Hills where highs will reach 95F to 100F. - Shift to Mixed Wet/Dry Storms: Drier air aloft will limit overall storm coverage today and Friday, favoring a mix of isolated wet and dry thunderstorms. Convection targets the Central Mountains and Continental Divide today before shifting toward the Utah border on Friday. - Saturday Shortwave & Gusty Winds: A passing shortwave on Saturday will briefly elevate shower and thunderstorm chances while generating widespread wind gusts of 30 to 40 mph. This could lead to Red Flag Conditions for parts of eastern Idaho. && .DISCUSSION... Issued at 129 PM MDT Thu Jul 23 2026 Afternoon satellite imagery presents a stark contrast to 24 hours ago, showing mostly clear skies across eastern Idaho. While gradual cumulus development is underway over the higher terrain, lower elevations remain virtually cloud-free. Clear skies coupled with an amplifying Four Corners ridge to our south will allow significant heat to return to the region. While afternoon highs today will remain near seasonal benchmarks in the upper 80s to lower 90s across valley locations, temperatures will quickly ramp up into the mid-to-upper 90s on Friday and linger through the weekend into early next week. In response, a Heat Advisory has been issued for Friday across lower-elevation zonesincluding the Snake Plain, Magic Valley, Arco Desert, Shoshone, and the South Hillswhere widespread max temperatures of 95F to 100F appear likely. Regarding precipitation, an intrusion of drier mid-level air will restrict overall storm coverage over the next 48 hours, prompting a transition back to a mix of wet and dry thunderstorms. High-resolution convective-allowing models (CAMs) highlight the Central Mountains and the Continental Divide as the primary focus for isolated afternoon development today. Convective activity is forecast to shift southward toward the Utah border on Friday. A passing shortwave trough will interrupt the dry-leaning pattern on Saturday, bringing an uptick in shower and thunderstorm potential. In addition to storm chances, the gradient will tighten, yielding widespread afternoon wind gusts of 30 to 40 mph across the forecast area. Behind this disturbance, the broad ridge will maintain its grip over the Intermountain West, keeping temperatures consistently above normal through early next week. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1210 AM MDT Fri Jul 24 2026 A shortwave will bring isolated to scattered convection to Southeast Idaho this afternoon, along with wind gusts over 30 mph. Storms will be capable of outflow winds 40 to 50 mph and heavy rainfall. Have included PROB30s for all sites between 21z Friday and 02z Saturday. && .FIRE WEATHER... Issued at 129 PM MDT Thu Jul 23 2026 High pressure is building back in over the area today after yesterday`s shortwave and monsoon moisture push. A few isolated thunderstorms will continue this afternoon, mainly being triggered by orographic lift off our mountains and afternoon heating. Overall, it will be a much drier day for most, but min RHs haven`t completely dropped from yesterday`s moisture. That will be more noticeable beginning tomorrow with min RHs areawide of 15 to 25 percent. Winds will be a bit breezy on Friday afternoon, too, with gusts around 20 to 25 mph. We will see near-critical fire weather conditions in parts of the Central Mountains in the afternoon, Fire Weather Zones 475 and 476. Winds get even more breezy on Saturday and another round of monsoon moisture looks to impact parts FWZ 410, 411, 413, and 427. So, Saturday looks like a day we may need Red Flag Warnings for a mix of low RHs and gusty winds 475 and 476 and a mix of wet and dry scattered thunderstorms in 410, 411, 413, and 427, but we will see how the next few model runs look later tonight and tomorrow. Overall, it doesn`t look like the pattern is changing much as we head into next week. && .PIH WATCHES/WARNINGS/ADVISORIES... Heat Advisory from 1 PM this afternoon to 9 PM MDT this evening for IDZ051>057. && $$ DISCUSSION...McKaughan AVIATION...Cropp FIRE WEATHER...AMM