Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
559 FXUS65 KPIH 251945 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 145 PM MDT Sat May 25 2024 .SHORT TERM...Today through Sunday Night. Early afternoon satellite imagery shows a H5 trough working through ERN Idaho which will continue to support isolated to scattered showers and thunderstorms through this evening ahead of drier conditions returning overnight tonight into Sunday. While overall rainfall totals so far today have remained on the lighter side, a weather station NE of Preston up towards Mink Creek recorded 0.84" of rain in just an hour this morning which goes to highlight the potential for heavy precipitation with more organized convection. Stronger storms while staying very isolated in nature today will support heavy rain, small hail, and wind gusts up to around 30-40 mph. As this H5 trough shifts east over the Continental Divide, we may see some continued isolated showers in NE Idaho up around Island Park and the Teton Valley but conditions will remain predominantly dry going forward heading into Sunday to round out the weekend. Drier, zonal flow will return for Sunday on the leading edge of a H5 ridge that is expected to shift east over the NRN Rockies for early next week. This will help to reintroduce a warming trend as conditions remain dry with the warmest air mass of the season so far looking to build into our region. Until then, highs this weekend will be in the 50s/60s with lows in the 30s/40s. Given elevated 700 mb winds aloft around 20-35 kts, a LAKE WIND ADVISORY remains in effect until 9 PM for American Falls Reservoir today with gusts up to 40 mph possible. An additional LAKE WIND ADVISORY may be needed again on Sunday as winds look to be just there again for a low-end issuance. Winds look to stay below WIND ADVISORY issuance both today and tomorrow with the strongest gusts around 25-45 mph, especially across the Snake Plain. MacKay .LONG TERM...Memorial Day through next Saturday. High pressure ridge aloft overhead with high pressure at the surface will provide a beautiful Memorial Day with sunny skies and highs in the 70s low elevations and upper 50s to lower 70s in the mountains. Ridge moves east Tuesday with southwesterly flow aloft bringing in much warmer air and almost all low elevation areas will have high temperatures in the 80s and mainly 70s in the mountains. With an slight increase in moisture there will be a slight chance of showers and thunderstorms late in the day. The main upper level trof will move through Wednesday with more widespread showers and thunderstorms and much cooler conditions moving in. A Canadian system passing to north will keep a slight chance of convective activity Thursday and Friday in the Central mountains and Upper Snake Highlands with dry conditions in the snake river plain and southern mountains. Dry conditions are expected next Saturday. High temperatures will be back down in the 60s and 70s Wednesday and all the way down to the 50s and 60s Thursday as the Canadian system passes to north. It should rebound nicely heading into the weekend with highs back to near normal Saturday well into the 60s mountains and 70s valleys. Wednesday and Thursday will be the windiest days as the upper level systems drive through cold fronts and widespread 25 to 40 mph wind gusts both days will occur. GK && .AVIATION...For the 18Z TAFS through 18Z Sunday. Upper level system working through eastern Idaho today and have showers and thunderstorms at DIJ and IDA early this evening and dry conditions at SUN and BYI as expect activity to be well east of them. DIJ will dry out tonight with dry conditions expected late tonight through Sunday at all sites with VFR conditions. Breezy conditions with 10 to 20 knot sustained winds this evenings at IDA, PIH and BYI and even SUN into early evening. The 10 to 15 knot speeds will likely continue overnight at BYI, PIH and IDA. 10 to 20 knots will continue at those sites Sunday. GK && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$