Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
682 FXUS65 KPIH 180943 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 343 AM MDT Wed Sep 18 2024 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT... The low pressure system responsible for yesterday`s cool, showery, cloudy conditions is tracking northeast into Montana which will support a drying trend for southeast Idaho, yet its close proximity may still produce some showers and even a thunderstorm or two today. Highest PoPs today lie north and east of a rough line from Hailey, to Blackfoot, to Georgetown, with only a couple isolated showers south and west of this line. Patchy fog is also possible. High temps will hold in the upper 50s to mid-60s. Our next in a series of low pressure systems still looks like it favors a track south and west of our forecast area, yielding growing confidence in dry conditions Thursday with temperatures inching up into the mid-60s to lower- 70s, and perhaps some more patchy morning fog. 01 .LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY... Models have been consistent in trending drier for the extended period. Split flow over East Idaho holds Friday through early Saturday, with weak trough to the north and closed low migrating east through the Great Basin but remaining well south of the region. Looking past the weekend into early next week, ensemble clusters begin to amplify ridge along the Pacific coast, slowly migrating it inland Tuesday. By Wednesday, there are some signs that the ridge could give way to a fast moving Pacific system. Overall, pattern through the extended favors drier conditions with temperatures remaining below seasonal normals. DMH && .AVIATION... A mix of VFR/MVFR conditions is expected across most of the region as a low pressure system slowly works northeast out of Idaho. Plenty of moisture over the past two days is available for potential fog/stratus formation early this morning. Terminals most likely affected would be KDIJ and KIDA with low confidence/brief IFR, less likely at KPIH and KBYI. Northwest downslope flow should keep low stratus out of KSUN. Some pockets of clearing will also allow pockets of instability for additional showers and a few thunderstorms today, mainly for KDIJ, but could stretch as far west as KIDA and VCSH for KSUN. Breezy winds early diminish through the afternoon and evening. The showers could continue through the evening at KDIJ, but all precipitation should be cleared after 06Z tonight. Depending on clearing, there could be another potential round of fog/stratus overnight, but very low confidence right now so keeping CIGS MVFR/VFR for now. DMH && .FIRE WEATHER... Low pressure system continues slow shift out of the region, with precipitation lingering across the northeast corner of the district today. A few thunderstorms will be possible. Breezy winds early today diminish through the afternoon and evening. A drying trend is expected into the weekend, though an isolated shower cant be completely ruled out day to day over higher elevation areas. Models generally agree on building a ridge over the western states early to mid next week, but position and strength of the ridge still varies slightly in the model solutions. In general, pattern should remain influences by dry northwest flow, with temperatures remaining below seasonal normals. DMH && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$