Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
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519 FXUS65 KPIH 302204 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 404 PM MDT Thu Jul 30 2026 .KEY MESSAGES... - Risk of thunderstorms diminishes tonight and Friday afternoon/evening. - Stronger wind Saturday and Sunday combines with very low humidity for Red Flag conditions likely. - Saturday highs will challenge the century mark in lower elevations. && .DISCUSSION... Issued at 1204 PM MDT Thu Jul 30 2026 High pressure has strengthened after the weak trough passed through last Wed afternoon/evening. A very unstable air mass over eastern Idaho along with good amounts of moisture as evidenced by the dewpoints above 50 deg F. This should trigger a penultimate round of thunderstorms for the remainder of the afternoon and into the evening tonight. However, a shift in the upper level wind to a more westerly direction will cut off the supply of this unstable moist air and by Sat the risk of any precipitation anywhere in the forecast area drops to zero and stays that way through at least next Thu. Lack of clouds will allow hit temperatures to return by Sat, with forecasts of at least the upper 90s for elevations below 5500ft and some places exceeding 100 deg F on Sat. There is a slight cool down on Sun as a dry cold front centered in western Canada moves through eastern Idaho longitudes. The main effect will be to increase the wind for Sat and Sun. This should mean critical fire weather issues discussed below. After the Canadian front departs the west, the upper level flow continues out of the west and northwest. This means much drier air and an end to thunderstorm activity. The cooling trend also continues into Mon afternoon as even Snake River plain temperatures only warm into the 80s. The west and northwest flow slows the warming, but by Wed temperatures will be back above 90 for the lower elevations. High pressure will keep wind light to with moderate gusts in the afternoon possible. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 404 PM MDT Thu Jul 30 2026 Scattered thunderstorms may impact TAF sites tonight with a 30% probability. Gusty outflow winds and heavy downpours reducing visibility are main impacts. Expect conditions to improve after 02/03Z. && .FIRE WEATHER... Issued at 1157 PM MDT Wed Jul 29 2026 Monsoon moisture continues to be tough to fully push out of here, as it now appears we may even see a few storms on Friday. The overall chance is dwindling though as deeper moisture is on its way out of here. The pattern today looks similar, spatially, as the best chance of storms will be across higher terrain. There will likely be some spillover into the Snake Plain along outflow boundaries and stronger storms holding together. There is some potential for some decent downpours, but it doesn`t appear as widespread and likely as Wednesday. There is a 30-70% chance for gusts over 35 mph today, peaking at 45-50 mph. Those chances are even lower tomorrow, at 10-40% as coverage becomes more isolated. Temperatures will continue to warm up, with highs peaking Saturday. Valley temperatures will push 95-105, with mountain temperatures in the 80s. Very dry air moves as the monsoon moisture shifts away from us. We are expecting a classic breakdown of the ridge after a prolonged period of southwest flow and monsoon driven thunderstorms. This takes place Sunday, with strong westerly flow developing and locking into place for next week. This will drop temperatures initially early next week, BUT dry air remains in place. Winds will be increasing for the Saturday-Monday timeframe, but remain elevated beyond that. Looking at the potential for Red Flag conditions, we will pushing that today with borderline scattered thunderstorms across Zones 413 and 427. Coverage will be isolated tomorrow, so no issues expected other than maybe holdovers. We will likely see critical fire weather conditions across the central mountains, much of the Snake Plain and across Zone 411 on Saturday. The potential spreads south into the Magic Valley and pockets of Zones 413 and 427 on Sunday due to strong winds and very low humidity. Critical to near-critical conditions are possible almost daily next week. && .AIR QUALITY... Issued at 100 PM MDT Thu Jul 30 2026 Air quality alerts continue for Custer and Butte Counties for the next 24 hours due to proximity and ideal trajectory of smoke from wildfires. Blaine, Lincoln, Minidoka, and Cassia County advisories have been lifted. && .PIH WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday afternoon through Sunday evening for IDZ410-422-425-475-476. Air Quality Alert until 3 PM MDT Friday for IDZ052-067>074. && $$ DISCUSSION...Messick AVIATION...13 FIRE WEATHER...Keyes AIR QUALITY...Messick