Area Forecast Discussion
Issued by NWS Pocatello, ID
Issued by NWS Pocatello, ID
370 FXUS65 KPIH 292000 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 200 PM MDT Wed May 29 2024 .SHORT TERM...Today through Thursday night. Cold front has shifted through East Idaho, with upper trough axis working through. Radar shows mainly isolated thunderstorm activity so far along the Montana border. CAPE around 1000 J/kg, shear 35-40 kts, and steep lapse rates in lowest levels all support gusts over 50 mph and hail around 3/4". Bear Lake another potential region for development this afternoon into early evening, but cloud cover so far today may limit potential instability and inhibit strongest development. Added small hail/gusty wind/heavy rain wording to the thunderstorms through the remainder of today. Gusty non- thunderstorm winds remain a concern across the Snake Plain, where steep gradient coincides with clearing and mixing of stronger winds aloft. Wind Advisory remains in place through the early evening, when gradient relaxes and strongest winds subside. Cooler airmass in place behind this front, and temperatures drop cold enough to support yet another night of Frost headlines for portions of the Snake Plain. Coldest temperatures will be from Shoshone-Arco-Mud Lake-Rexburg, with much of the populated I-15/I-86 corridor expected to be warmer than the 36F threshold for frost. Weak broad trough remains in place over the region into Thursday/Thursday night, allowing for the coldest period as drier and clearer air mass works into the region. Gusty winds in place one more day, but should be below any Advisory thresholds, including for American Falls Reservoir. May need another night of Frost headlines for portions of the Snake Plain for Thursday night. DMH .LONG TERM...Friday through Wednesday. Brief ridge of high pressure continues into Friday as temperatures nudge back up into the high 60s/low 70s for most lower elevations. Ridge breaks down Saturday as weak shortwave drives through the region for next chance at showers/thunderstorms and a bit of wind mainly late afternoon into the evening. Temperatures Saturday surge into the upper 70s/lower 80s before dropping slightly again Sunday as remnants of the shortwave feature slide through. Ensemble clusters show strong agreement on relatively flat but progressive flow for Monday into Tuesday. Monday should be the wettest and day as main feature shifts through the region, with lingering showers mainly eastern areas Tuesday. Both days looks breezy to windy. Next ridge builds beginning Wednesday, with clusters in good agreement for a higher amplitude ridge axis developing through the Intermountain West or Coastal states through the remainder of the week. DMH && .AVIATION...Another day with mixed conditions across East Idaho as a frontal system slides through the region. Windy conditions through the Snake Plain impacting KBYI/KPIH/KIDA with sustained winds 20-25kts and gusts around 35kts. These winds are expected to continue into early evening before subsiding. A few thunderstorms have developed north along the Montana border, but showers and a few thunderstorms remain possible along the Wyoming border south to the Bear Lake area through early evening as well. Small hail and gusty winds around 45kts are possible. All wind and thunderstorm activity is expected to diminish before 06Z, with winds gradually decreasing to around 10kts overnight. VFR CIGS are expected throughout, though MVFR is likely in the vicinity of stronger thunderstorms. DMH && .PIH WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 9 PM MDT this evening for IDZ051>055. Frost Advisory from 3 AM to 9 AM MDT Thursday for IDZ051>053. && $$