textproduct: Pocatello

KEY MESSAGES

- Unsettled conditions return Monday and Tuesday.

- Lake Wind Potential Tuesday.

- Another round of Frost/Freeze Wednesday AM.

DISCUSSION

Issued at 1252 PM MDT Sun May 3 2026

Satellite imagery shows split flow pattern with deep low off California coast and shortwave dropping through Montana in northern stream flow. There is still a low chance of seeing isolated convection this afternoon across higher elevation areas, but surface dew point depressions are quite low. Confidence leans toward virga showers with an occasional sprinkle this afternoon and early evening. Split flow collapses slightly into Monday as coastal low shifts inland slightly and starts to open, allowing moisture to pull north into East Idaho. Thunderstorm activity increases, especially across the southern highlands. Sounding profiles look favorable for gusty winds with potential for brief moderate rainfall, though most areas will see little precipitation.

Shortwave feature for Tuesday drops frontal boundary south across the forecast area early in the day. Showers and isolated thunderstorms continue mainly over higher terrain. Slightly cooler temperatures and gusty northerly flow will be in place. For winds, blended above NBM deterministic towards the 75th percentile, keeping forecast below general Wind Advisory criteria. But, a Lake Wind Advisory will likely be needed for American Falls Reservoir, with rough chop piling up at the south end near the dam under the influence of the northerly winds. Another night of frost/freeze is looking more confident as NBM probabilities support more than 50% chance of overnight lows dropping below freezing for the northern portions of the Snake Plain Tuesday night/Wednesday morning. It does look like a one- and-done cold snap as upper ridge rebounds for the remainder of the week with a return to a warming trend and a greater than 50% chance of several areas meeting or exceeding 80 degrees for highs by Friday. GFS and ECMWF models this morning continue to show shortwave pushing through the PacNW and across Montana late Friday into the weekend, collapsing the ridge and reintroducing unsettled conditions to East Idaho for the weekend.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1141 AM MDT Sun May 3 2026

We are looking at more VFR weather, although we should see an increase in afternoon cloud buildup today and tomorrow. For today, it is very dry below the cloud layer and this would indicate virga and quick burst of wind vs actual moisture (other than sprinkles) falling. Even if we do get a shower or storm to impact a particular airport, it would be around 10% or less, and would most likely be at SUN or DIJ.

PIH WATCHES/WARNINGS/ADVISORIES

None.