FXUS65 KPIH 152341 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 541 PM MDT Wed Apr 15 2026 .KEY MESSAGES... - Impactful Frontal Passage: A cold front will sweep through the region tonight, causing snow levels to plummet to valley floors by Thursday morning. - Winter Weather Headlines: Winter Weather Advisories remain in effect for the central mountains, the Island Park area, and the Bear River Range, where the heaviest snow is expected. - Wind Advisory Today: Strong winds will continue into the evening, with an advisory in effect for the Arco Desert and Lemhi Highlands. - Hard Freeze Potential: A Freeze Warning has been issued for the Magic Valley, Snake Plain, Arco Desert and Shoshone zones for Thursday and Friday mornings with a widespread Hard Freeze looking likely by Friday morning. - Strong Warming Trend: Following the midweek cold snap, a significant warm-up is forecast for the weekend, with temperatures rising well above seasonal norms by Sunday. && .DISCUSSION... Issued at 142 PM MDT Wed Apr 15 2026 Drastic pattern change is underway as a cold late-winter system descends on East Idaho. Satellite water vapor imagery shows closed low off BC Canada coast with moisture plume streaming through Idaho. Shortwave axis visible draped along PacNW coast. Radar shows moisture slowly filling in across East Idaho, but surface dew point depressions remain steep outside of the higher elevation areas, so precipitation may take some time to develop for the Snake Plain and lower elevations. Lastly, winds remain gusty across portions of the Upper Snake Plain region, and a WIND ADVISORY remains in place into the evening. Focus for precipitation through midnight remains across the Central Mountains and Island Park region. Afternoon snow levels around 6500 ft in the Central Mountains rise to around 7500 ft across the southern highlands, but rapidly fall behind strong cold front driving through the region overnight. This brings snow down to valley floors for most areas by Thursday morning. Snow totals still remain strong enough over high elevations to produce mild travel impacts above 6500 ft, so will maintain the current WINTER WEATHER ADVISORY as well. Snow showers become more plentiful during the day Thursday, even at lower elevations, with highs expected to top out in the mid 40s for most locations. Winds remain gusty behind the front, but should remain below Advisory criteria. Additionally, high- res models continue support for 2nd frontal feature/convergence zone late Thursday that will likely help produce the best chance for accumulating snow in the Snake Plain. Road temperatures remain quite warm and accumulations remain below 2" even across the Upper Plain, so at this time we expect minimal travel impacts, and will hold off on additional headlines for now. Potentially one of the biggest impacts will be the cold temperatures following the cold front, beginning tonight and continuing into the weekend, especially after prolonged warmer than normal period. Overnight lows throughout the Snake Plain range 28-32 degrees, supportive of a FREEZE WARNING. Given the even colder temperatures for Thursday night, have already upgraded the FREEZE WATCH to a FREEZE WARNING. For the Thursday night/Friday morning lows, the lows are supportive of a HARD FREEZE, with widespread lows in the lower to mid 20s. Given the early growing season this year, these extremely low temperatures are expected to be particularly impactful. We believe that additional headlines will be necessary even into Saturday and potentially Sunday morning, but will address with upcoming packages. Looking into the weekend and early next week, dry conditions are expected with a warming trend into early next week. Overnight lows do rise back above freezing again by Monday morning. Ensemble means support another trough shifting into the western US by mid week next week. Precipitation chances return as early as Tuesday with more confidence by Wednesday. There is quite a bit of spread among the ensembles especially by Wednesday with respect to progression of the trough through the west, so expect some fluctuation in the forecast until confidence increases. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 532 PM MDT Wed Apr 15 2026 Cold front and associated low are wreaking havoc with CIG and occasionally VSBY at all airdromes. There appears to be something of a break with improved (but not necessarily VFR) conditions during this evening, but a resurgence appears likely during the overnight hours starting around 16/04Z at KSUN to 16/06Z in the east. Partial clearing appears to develop first at KSUN just as operations re-start in the morning, while other airdromes will have to wait until the mid- to late morning hours. Only KDIJ appears to have a risk of IFR conditions with most others only dealing with marginal VFR. Wind will actually stay elevated most locations save KSUN. 15G25KT will occur quite a bit overnight, with KIDA having some 20G30KT. Then during the day KBYI, KPIH, and KIDA all deal with 20G30KT. Fortunately it hasn't got much crosswind component for the primary runways. && .PIH WATCHES/WARNINGS/ADVISORIES... Freeze Warning from 3 AM to 10 AM MDT Thursday for IDZ051>055. Freeze Warning from 3 AM to 10 AM MDT Friday for IDZ051>055. Wind Advisory until 9 PM MDT this evening for IDZ052-067. Winter Weather Advisory until 6 AM MDT Friday for IDZ060-066. Winter Weather Advisory until noon MDT Thursday for IDZ071>074. && $$ DISCUSSION...DMH AVIATION...Messick