208 FXUS65 KPIH 141120 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 520 AM MDT Mon Apr 14 2025 .KEY MESSAGES... - High pressure will produce warm, dry weather into midweek. - Increasing confidence in next storm system for mid to late week with return to cool unsettled conditions. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 140 AM MDT Mon Apr 14 2025 Upper ridge will begin to build into the area today. We should see above normal temps today as highs in the Snake Plain and Magic Valley in the 60s today and even warmer on Tuesday with highs in the 70s. The NAM is trying to develop thunderstorms from some mid level moisture to our south late Tuesday afternoon, pushing the remnants into southern Idaho Tuesday night. The GFS/European aren`t as aggressive with the convection, but this is something to potentially watch. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 140 AM MDT Mon Apr 14 2025 Wednesday is shaping up to be a transition day between above normal temperatures and dry conditions to start the week to a return to precipitation chances and cooler temperatures starting Thursday as a split 500 mb trough builds east from the Pacific. Conditions will stay dry to start the day Wednesday ahead of isolated showers moving in for the afternoon and evening hours. Winds will also increase during that timeframe as 20-35 kt 700 mb winds aloft support winds peaking around 10-25 mph with gusts to 25-40 mph. Highs on Wednesday in the 60s/70s will drop about 15-20 degrees for Thursday with highs returning to the 40s/50s associated with our next system moving in. As this split trough continues its progression east on Thursday, two well defined areas of low pressure are expected to develop with one dropping south through the northern Rockies and another working east through the southwest CONUS. The northerly of these two lows will be the driver of isolated to scattered precipitation chances throughout the day Thursday with widespread cloud cover and gusty winds allowing for much cooler, below normal temperatures as this low tracks south through the PacNW and northern Rockies. Snow levels initially starting up in the mountains will progressively fall to valley floors throughout the day Thursday into Thursday night, supporting a mix of rain and snow showers regionwide. 48-hour rainfall/SWE totals from late Wednesday through early Friday have remained consistent with previous forecasts, showing a T-0.25" in the valleys and 0.25-0.75" in the mountains. Snowfall amounts during this timeframe will remain light with a T-1" possible in the valleys and 1-4" in the mountains, locally higher in that 4-6" range. Winds on Thursday will also remain elevated courtesy of a backdoor cold front dropping northeast to southwest with breezy northerly winds expected in the Central Mountains, Upper Snake River Plain, and Eastern Highlands while winds remain out of the west or northwest for locations further south. Winds will peak Thursday afternoon/evening and will remain elevated into Friday morning. Winds during this timeframe look to peak around 15-35 mph with gusts to 30-50 mph, strongest across the Upper Snake River Plain and eastern Central Mountains. Given our typical W/SW wind events and more atypical stronger N/NE winds, these winds will be something to watch for a potential Wind Advisory issuance. For those areas starting off with W/NW winds, we will see a transition over regionwide to N/NE winds Thursday night into Friday morning. With this 500 mb low dropping south through the Great Basin for Friday, a ridge of high pressure is expected to begin building into the northern Rockies with drier conditions back for Friday building in northwest to southeast as isolated to scattered showers persist. Temperatures will see a warming trend heading into the weekend as the ridge axis shifts overhead with highs back in the 50s/60s. With this ridge feature weakening and shifting east for Sunday, this will set the stage for several waves of moisture to build in out of the northeast Pacific and western Canada, supporting daily precipitation chances back in the forecast starting Sunday into early next week. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 520 AM MDT Mon Apr 14 2025 Predominant VFR and dry conditions with light winds and clear skies will continue across southeast Idaho into Tuesday under the increasing influence of high pressure overhead. && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...13 LONG TERM...MacKay AVIATION...MacKay