219 FXUS65 KPIH 161902 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 102 PM MDT Wed Apr 16 2025 .KEY MESSAGES... - Last warm day today. - 20 to 30 degree drop in temperatures on Thursday with light snow possible even down to valley floors. - Gusty north winds Thursday afternoon across upper Snake Plain. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 101 PM MDT Wed Apr 16 2025 The next two days can be summarized as Spring followed by Winter as drastic changes are expected across eastern Idaho over the next 12- 24 hours. Afternoon satellite imagery shows a potent shortwave and developing area of low pressure moving out of British Columbia this afternoon. As it stands currently, skies remain mostly sunny around the region but clouds will be on the increase throughout the evening and overnight as this feature moves quickly towards our area. Temperatures remain 10-15 degrees above normal with widespread 60s in place, some spots topping out in the lower 70s before the day is done. Hi-res CAMs continue to the potential for some showers, maybe a thunderstorm, sneaking out of the Great Basin later this afternoon/evening potentially impacting some our southernmost area along the Utah border and over towards the Bear Lake region and into the southeast highlands. CAMs don`t have much of these making it`s way in to the Snake Plain anymore although it can`t be entirely ruled out. The better surge of moisture will be during the overnight and into the early part of the day Thursday when colder air will come blasting into the area with the snow possible down to valley floors as early as sunrise tomorrow. This system won`t have a ton of moisture with it but a tenth or two of QPF will be possible, locally higher across some of the higher terrain in the east, but this isn`t going to be a huge precipitation event for us. Given the fact that we`re in the 60s and 70s this afternoon and marginal temperatures tomorrow, we`ll be hard-pressed to get any of this snow to stick to area roadways tomorrow but some very light accumulations on elevated and grassy surfaces isn`t out of the question. Across the higher terrain of the eastern/southeastern highlands, a few inches of slushy snowfall can be expected, especially any elevations above 6500 feet or so. Going back to temperatures, daytime highs tomorrow will be 15 to 25 degrees COLDER than today with most areas not expected to get out of the 40s. So we`ll go from 10-15 degrees above normal today to 10-15 degrees below normal tomorrow. The colder temps and precip weren`t enough, it`ll also be windy tomorrow with Wind Advisories continuing across the Arco Desert, Lost River Valley and into the Lemhi Highlands. Winds in the Snake Plain look to remain just below advisory criteria but it will still be breezy nevertheless but it`ll make it feel even colder with our apparent temperatures likely staying in the 20s and 30s for much of the day tomorrow. A big change indeed from today`s pleasant weather! Such is Spring in the intermountain west! Things will begin to improve slowly Friday and even more so by the weekend. More on that below.&& .LONG TERM /FRIDAY THROUGH TUESDAY/... Issued at 101 PM MDT Wed Apr 16 2025 It will start out very cold on Friday in the long term period with highs mainly 30s to mid 40s mountains and 40s to lower 50s valleys still about 10 degrees below seasonal averages. There will be lingering snow showers in the southern and eastern mountains but little additional accumulation during the day as temperatures warm. Saturday will be dry as weak upper level ridge moves through Idaho with highs back around seasonal average with 40s and 50s mountains and 50s to lower 60s valleys after lows Friday night in the teens and 20s mountains and 20s valleys. Sunday through Wednesday will see a series of fast moving upper level short waves move through Idaho with at least a chance of showers daily mainly in the eastern mountains with snow levels varying between 6 and 8 thousand feet through the period. Temperatures will be right around average Sunday through Tuesday in the 40s and 50s mountains and mid 50s to lower 60s valleys. Expect warming Wednesday to well above normal with parts of the Snake Plain and Magic Valley approaching 70 once again. Lows in the 20s and 30s Sunday night through Tuesday night. Sunday and Monday will be breeziest days with 10 to 20 mph sustained winds across much of the region with gusts occasionally over 30 mph. Lighter winds expected Tuesday and Wednesday.&& .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1103 AM MDT Wed Apr 16 2025 Will see winds increase this afternoon to 10 to 15 knots at BYI, PIH and IDA with gusts 20 to 25 knots at PIH and IDA with southwest winds after 20Z at SUN. Cold front moves through Thursday and expect winds to continue with the 10 to 15 knots and gusts 20 to 30 knots late tonight early Thursday with frontal passage. AT this point expect VFR conditions continue through Thursday morning with only VCSH for the most part at all sites overnight into THursday with only predominate -SN at DIJ Thursday morning as much colder temperatures move in. && .PIH WATCHES/WARNINGS/ADVISORIES... Wind Advisory from noon to 9 PM MDT Thursday for IDZ052-067- 068. && $$ SHORT TERM...McKaughan LONG TERM...GK AVIATION...GK