textproduct: Pocatello

KEY MESSAGES

- Winter Weather Advisories are in effect for portions of the Central Idaho mountains. Winter weather advisories start at noon today for portions of the southeast and east highlands.

- Wind Advisories go into effect at noon today for portions of the Snake River plain and eastern Magic Valley.

- Afternoon highs drop 20 to 25 degrees from Tuesday highs and stay below normal through Monday.

- Rain and high elevation snow continues into Friday for most.

DISCUSSION

Issued at 153 AM MDT Wed Apr 22 2026

Today through Fri night. Melted precipitation amounts peak during the day today as a cold front is pushed through the region by an upper level low moving through northeast OR that ends up in western MT by mid-day. A second low drops southward out of Canada and brings another round of precipitation for Thu with almost no break in the precipitation. The northwesterly air flow behind this low continues Thu night but shifts to westerly on Fri afternoon. Because of the below normal-but still warm-temperatures, snow levels continue high with moderate to heavy accumulations occuring somewhere between 6500ft and 7500ft elevation, depending on how far south.

One fly in the ointment is how the precipitation is strongly affected by convection. There will be enough instability for thunderstorms each period in this portion of the forecast.

This cold front is powered by a large temperature difference between the air masses. A drop of 20 to 25 deg F will occur between Tuesday and today. Afternoon highs stay below normal for the next 6 days, getting closer to normal next Tue. Overnight lows stay mild tonight with cloud cover, but as the cover thins on Thu night, lows drop into the 20s for a widespread area. This also continues through Fri night, then below 38 deg F for Sat night. Thus Freeze and later Frost Advisories may be needed for the agriculturally sensitive areas.

Sat through Tue. Clusters continue to keep an upper level low either overhead of just to the east of the forecast area. This means the precipitation threat and colder than normal temperatures continue due to clouds and a northerly flow. By Sat a significant minority of the clusters show a far enough progression eastward for the risk of precipitation to fall to slight chance/chance level and temperatures at least to warm slightly, even if they stay mainly in the 50s for the heavily populated areas. Wind also is considerably less, with breezy conditions in the afternoon and early evening.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 423 AM MDT Wed Apr 22 2026

Not a great day for aviation. Mostly rain expected at all airdromes with KSUN, KBYI, KPIH, and KIDA all to risk IFR conditions due to CIG, with KSUN at high enough elevation that SHSN may also impact VSBY. KDIJ should see occasional snow this morning, but CIG is expected to stay marginal VFR along with VSBY. This will change tonight after 23/06Z for KDIJ as temperatures and snow level falls, but snow will be light that late night.

The main forecast problem though will be wind. Very strong southwest wind will mean a turbulent approach with G35KT to G40KT for all airports except KSUN where down valley wind in the early evening will produce G30KT.

PIH WATCHES/WARNINGS/ADVISORIES

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