textproduct: Pocatello

KEY MESSAGES

- Return to winter like weather in the high elevations. Winter Weather Advisories for portions of the central Idaho mountains and the highlands bordering Wyoming above 6500ft elevation.

- Cold front on Wednesday will bring wind strong enough to produce Wind Advisory criteria in Arco and Mud Lake Desert along with Snake River Plain. Isolated thunderstorms are also possible.

- Rain and occasional snow possible elsewhere starting late tonight and continuing through Thursday night, changing to showery afterwards.

DISCUSSION

Issued at 117 PM MDT Tue Apr 21 2026

Main impact is going to be a strong cold front moving through eastern Idaho in the early morning hours on Wednesday. Rain and high elevation snow will move into the central mountains after midnight and have winter weather advisory with a near 50 percent chance of 6 inches of snowfall above 6500 feet. Will see a wind increase also after noon on Wednesday with 25 to 35 mph likely in the Snake Plain, and Arco and Mud Lake desert region. A winter weather advisory with the same likelihood of 6 inches begins at noon Wednesday for the eastern mountains also above 6500 feet. Will see at least a slight chance for thunderstorms as well Wednesday afternoon with the frontal passage. Much colder weather will move in quickly behind the front Wednesday with afternoon highs 30s and 40s mountains and 40s to lower 50s valleys. Lower elevations will see rain showers with snow levels right around 6 thousand feet. Will get a second upper level trof and surface front Thursday keeping high level snow showers and low level rain showers going especially in the eastern mountains and the winter weather advisory continues there through Thursday evening. Breezy to windy conditions also continue on Thursday wtih widespread 20 mph or greater speeds and gusts 30 to 40 mph continuing. Widespread sub freezing temperatures expected in valleys both Thursday night and Friday night so more freeze warnings are likely later this week. Expect some drier conditions Saturday through next Tuesday but have at least a chance of showers. The cooler trend will continue with high temperatures generally near or below normal Saturday through next Tuesday with a slight warming trend by early next week after the cold and well below normal temperatures Wednesday through Friday.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 448 PM MDT Tue Apr 21 2026

Impact this late afternoon will be wind, with wind remaining elevated throughout the period. Models do show a brief drop off in winds early this evening before quickly ramping up again this evening and continuing into tomorrow. Rain showers will finally reach central Idaho overnight/early morning Wednesday and spread further east early day. VFR CIGs will trend MVFR at all terminals during the day Wednesday with brief IFR conditions possible with heavier showers. VIS forecast to remain VFR at all terminals in rain or rain showers before KSUN and KDIJ transition to snow late Wednesday afternoon/early evening behind the cold front. Models do show a line of convective showers moving across the area starting late morning/early afternoon for SUN and BYI and mid afternoon for PIH and IDA and mid to late afternoon for DIJ. Have put in a PROB30 group for TSTMS. Initially thunderstorm chances looked like a 20 to 40 percent chance. Models are trending slightly higher, 50 to 60 percent chance of TSTMS for PIH, IDA and DIJ. So, may be adding in a predominant line for TSTMs in the afternoon Wednesday for PIH, IDA, and DIJ.

PIH WATCHES/WARNINGS/ADVISORIES

Wind Advisory from noon Wednesday to midnight MDT Wednesday night for IDZ051>054. Winter Weather Advisory from noon Wednesday to midnight MDT Thursday night for IDZ060-063-064-066. Winter Weather Advisory from midnight tonight to 6 AM MDT Thursday for IDZ069-071>074.