238 FXUS65 KPIH 311122 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 522 AM MDT Sat May 31 2025 .KEY MESSAGES... - Some record high temperatures for the date expected today. - Cooling trend starts Sunday with cloud cover and a risk of showers and thunderstorms Sunday night. - Sunday night through Tuesday night will be much cooler with some light precipitation expected, including thunderstorms. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 122 AM MDT Sat May 31 2025 Shallow upper level ridge slides east today and weak westerly flow aloft will move into region. It will be very warm today with valley highs in the mid 80s to lower 90s. Mountain highs in the 70s to lower 80s. Not expecting any precipitation today. Lows tonight in the 50s valleys and 40s mountains. It will be warm again Sunday with highs in the 70s mountains and 80s valleys. An upper level trof moves on shore from the Pacific Sunday and southwesterly flow combined with instability will bring showers and thunderstorms back into the forecast grids Sunday afternoon and Sunday night with the best chances in the central mountains and eastern mountains. Expect an increase in winds with the system Sunday as well with widespread 10 to 20 mph sustained winds in the Magic Valley and Snake River Plain into the central mountains. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 122 AM MDT Sat May 31 2025 Next week continues to look cooler (kicking off within 5 degrees of climatological normals for early June through Wednesday, then slowly trending warmer with some 80s returning for high temperatures at lower elevations Thursday onward), as well as less impactful in terms of wind and precipitation. The entire week will be dominated by broad/longwave troughing with a few embedded shortwave troughs pushing through, but these will largely just support chances of isolated to scattered showers and thunderstorms focused in some of our mountains and along the Wyoming border corridor. Regionally the best chance of more widespread showers and thunderstorms will be Tuesday afternoon, especially across the Central Mountains, eastern highlands, and upper Snake Plain. Otherwise, Monday looks a bit breezy in the eastern Magic Valley into the Raft River region, and overall QPF amounts throughout the week appear light. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 522 AM MDT Sat May 31 2025 High pressure ridging will hold on today, supporting high forecast confidence in dry, mostly clear/sunny, hot, VFR conditions with very light winds. No concerns for aviation through this evening. Westerly winds will start to increase at KBYI prior to sunrise Sunday as a trough of low pressure approaches the region. This will eventually lead to breezier conditions regionwide Sunday afternoon with a chance of at least isolated thunderstorms. While the best chance of thunderstorms will reside in mountain areas (especially north of KSUN and KIDA), potential may get close enough to a few terminals to eventually necessitate PROB30 -TSRA or VCTS in the TAFs, especially after 21z/3pm Sunday afternoon based on the latest HREF CAMs. Strong, gusty, erratic downdraft/outflow winds will be a concern with any storm. && .FIRE WEATHER... Issued at 122 AM MDT Sat May 31 2025 Will have a hot and dry day today with some minimum humidity below 15 percent in zones 475 and 476 and 425 and 427. Will see an increase in winds Sunday with thunderstorm development as well with most thunderstorms in zones 475, 476 and 411. Other zones will see isolated activity through Sunday night. Humidity will rise a bit Sunday with minimum in the 20 to 30 percent range. Expect much cooler temperatures Monday through Wednesday with at least isolated showers and thunderstorms. Sunday will be breezy in zones 425 and 419 with 10 to 20 mph sustained winds with 20 to 30 mph gusts. && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...GK LONG TERM...KSmith AVIATION...KSmith FIRE WEATHER...GK