textproduct: Pocatello

KEY MESSAGES

- Frost & freeze conditions persist through the rest of the week

- Increasing chance of showers and thunderstorms Wednesday afternoon and Thursday

- Temperatures return to 10-15 degrees ABOVE AVERAGE over the weekend

DISCUSSION

Issued at 1209 AM MDT Wed May 20 2026

Trends still point toward an increasing chance of showers and thunderstorms later today and continuing through Thursday afternoon. Low pressure drops south out of Canada and actually deepens as it swings across the state. At the moment, we may see little to no chance of precipitation once we get into the Stanley Basin and Wood River Valley. Precipitation amounts range from just a few hundredths to closer to 0.25" across portions of the eastern and southeast highlands. In reality, wherever we can get heavier showers or bands to develop, 0.25" can easily be achieved through tomorrow. Looking at probability forecasts, the higher end amounts in any given 12 hour period do indicate that 0.30-0.50" could occur in these situations. It will be breezy occasionally in the next 36 hours, with the only impact coming Thursday with gusty northeast winds on American Falls Reservoir. We will likely exceed thresholds for a northeast wind event and a LAKE WIND ADVISORY needed down the road. It will be just cold enough that we will will see some light snow accumulations on highest peaks and ridgelines as well. It looks like frost/freeze conditions (outside of typical colder spots this time of year) may linger through Saturday morning. We have a FREEZE WARNING and FROST ADVISORY for the Snake Plain and Magic Valley for this morning. For tonight, a FROST ADVISORY may be needed for portions the Arco Desert and INL area. Friday morning will likely see freeze conditions across most of the Snake Plain, and frost conditions in rural spots Saturday morning.

We do eventually warm back up, but it won't be until we return to southwest flow over the weekend and early next week. We will be well into the 70s and 80s for afternoon highs. With the next low moving into the region starting Tuesday, we will quickly drop back into the 60s (based on the latest Blend of Models forecasts) by midweek. We will likely also not be shower or storm free ahead of that storm. We continue to see small surges of moistures which COULD set of a few light showers/sprinkles and thunderstorms. Right now, we are keeping any potential at 15% or less until Tuesday.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 920 PM MDT Tue May 19 2026

Winds have settled down for the night. A few mid to high level clouds may drift over the sites overnight. Expect winds to increase mid to late afternoon with increasing clouds through the day. SUN should turn upvalley around midday with a gradual turn to the southwest late in the afternoon.

PIH WATCHES/WARNINGS/ADVISORIES

Frost Advisory until 9 AM MDT this morning for IDZ051-053>055. Freeze Warning until 9 AM MDT this morning for IDZ052.