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 /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1101 PM MDT Tue Apr 21 2026

A strong cold front is sweeping through the area tonight. It is bringing strong wind gusts to around 35-45 kts at many sites upstream and moving into the eastern Magic Valley and Snake River Plain. It will eventually bring showers and thunderstorms to all TAF sites, too. Models currently show showers arriving at KSUN and KBYI as early as 09Z tonight and at KPIH and KIDA a few hours later. Showers will continue on and off throughout the day with the potential for thunderstorms in the late morning to mid afternoon hours. KSUN and KDIJ will see a mix of rain and snow throughout the event while our valley locations will see almost all rain. Where we see snow, expect drops in VIS down to IFR conditions with IFR CIGs, too. KBYI, KPIH, and KIDA will be less likely to see IFR VIS, but are also expected to see CIGs fall to at least MVFR if not IFR levels. While the first blast of wind comes through with the cold front, it will be quite windy throughout all of Wednesday behind the front with gusts of at least 25-35 kts at all sites. Wrap around moisture/a convergence band of moisture looks likely after 06Z Wednesday night into Thursday.

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.