textproduct: Pocatello

KEY MESSAGES

- Dry weather expected through at least the middle of next week

- Fog and low clouds make a return tonight

- Temperatures remain fairly stagnant until the middle of next week

SHORT TERM /THROUGH TONIGHT/

Issued at 119 AM MST Sat Jan 17 2026

Looking at another day of dry weather with a ridge of high pressure locked in over us. Only concern is for morning fog. The HRRR shows fog developing after 10Z in the eastern Magic Valley and then rapidly expanding up the Snake River into the Idaho Falls region after 13Z. If this happens there could be some areas where visibilities could fall to 1/4 mile. For now, the patchy freezing fog in the forecast should suffice. Given uncertainty if the fog will develop, how fast, and how expansive.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 1151 AM MST Fri Jan 16 2026

Our pattern change is still expected to arrive by the middle of next week. Until then, even with the ridge beginning to weaken a bit...the forecast especially temperatures really won't be changing much at all. Once the pattern changes, we actually are looking at a warmup of sorts especially where inversions are expected to finally break...hopefully. It's not a huge warmup, but more areas will be in the 40s and keeping with the pattern of at or just above average. Precipitation chances really don't pick up until Thursday. That part of the forecast is really in flux simply because of the potential for split flow over the western states. There is some hint that we might see a closed low or at least the main low developing to our south and west. IF we do see that happen, the amount of moisture expected will be fairly low and just adding to our period of dry/mostly dry conditions.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 328 AM MST Sat Jan 17 2026

Widespread IFR ceilings is expanding from BYI to PIH and IDA this morning. There is some reduced visibilities as well but the ceilings are the main problem. Expect ceilings of less than 500 feet at these sites with models showing the moisture breaking up around 18z. Winds look light at all sites. Expect a wind shift from downvalley to upvalley at SUN by early afternoon.

AIR QUALITY

Issued at 1252 PM MST Thu Jan 15 2026

An AIR STAGNATION ADVISORY remains in place for the Pocatello area, our side of the Cache Valley, and south of Malad toward Samaria. We will continue to see limited mixing for the next several days. Something to watch will be with the ridge shifted west and northerly flow across central and eastern Idaho. It remains to be seen if that is strong enough to mix out inversions and "clear the air". We will leave things as is at the moment.

PIH WATCHES/WARNINGS/ADVISORIES

Air Stagnation Advisory until noon MST Sunday for IDZ054-059.