textproduct: Pocatello

KEY MESSAGES

- Showers and thunderstorms ending overnight west to east with brief downpours expected

- Warmer temperatures through Friday

- Breezy Friday afternoon followed by cooler weather this weekend with some potential for showers and storms

DISCUSSION

Issued at 1105 AM MDT Tue Sep 22 2026

Low pressure will continue shift northeast across Utah, Idaho, and Wyoming through tonight. Stronger showers and storms will produce heavier downpours, with the potential for 0.10"-0.20" in those situations or where multiple showers/storms move over the same location. The potential for anything over 0.20" is 30-60%, but that is not widespread and fits with the idea of showers/storms vs widespread precipitation. There isn't too much potential for gusty outflow winds, generally 10% or less, except around Bear Lake where the potential is pushing 50% through midnight.

We go back to dry and warmer conditions through Friday morning. Highs quickly bounce back into the 70s with some lower 80s mixed in Thursday and Friday. Friday into Saturday, low pressure swings by to our northwest. We should see some light rain showers and storms across the central mountains, but the main hazard will be stronger winds across all of central and eastern Idaho. Gusts of 20-35 mph will be common across the entire area, with some gusts around 40 mph possible across the Arco Desert, central mountains and along the Montana border. Saturday and beyond is a mess forecast-wise. The ECMWF continues to show a weaker low crossing Idaho early next week. The GFS wants to develop split flow and drag the low farther south. The caveat with the latest version of that model is that it's still far enough north to keep showers and storms in the forecast, AND also wants to clip the state with deeper tropical moisture from the Pacific. This would be coming from Hurricane Polo IF this pattern pans out. Needless to say, there potential forecast ideas is pretty wide ranging. The Blend of Models shows a gradual increase in showers and storms during that timeframe, which seems perfectly reasonable. Temperatures after Friday remain cooler, with valley highs in the 60s and lower 70s.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 523 PM MDT Tue Sep 22 2026

The chance of thunderstorms will persist through this early evening, around 2Z, for all TAF sites. Expect lingering showers until 6Z for all TAF sites except DIJ where showers could linger until around 10Z. Brief downpours are expected with gusts over 30 kts with any showers or thunderstorms on station. We could have some lingering low and mid level clouds tomorrow morning, but there is not a clear enough signal to drop to MVFR at this point. DIJ would be the most likely TAF site to see lower CIGS tomorrow morning. Expect clearing by mid afternoon tomorrow for all TAF sites except DIJ. DIJ will likely not clear until early tomorrow evening. Winds will remain light overall for all TAF sites.

FIRE WEATHER

Issued at 1105 AM MDT Tue Sep 22 2026

Showers and storms will continue into tonight, ending from west to east. Stronger showers and storms, or multiple storms over a given location, may produce 0.10-0.20". There is a 30-60% chance for higher amounts, BUT it would be spotty based on the pattern. We return to dry and warmer conditions quickly, and continuing through a good part of Friday. Low pressure swings by to our northwest, producing a few light showers and storms over the central mountains. The bigger impact will be increasing winds across the area. Wind gusts of 20-40 mph are expected, strongest across the Snake Plain (Zone 410), the central mountains (422/475/476) and along the Montana border in Zone 411. Humidity values at the moment should stay above 20% based on the current forecast trends. We do expect another round of showers and storms early next week. The question is will it be with a weaker low moving across Idaho, or with a deeper and slow low clipping us from the south. The latter idea also tries to pull in better moisture from Hurricane Polo, but even that current forecast only clips the state with the deeper moisture and keeps most it farther south and east.

PIH WATCHES/WARNINGS/ADVISORIES

None.