textproduct: Pocatello

KEY MESSAGES

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

- Fog and low clouds expected tonight

- A slight cooldown expected but temperatures still at or just above average

UPDATE

Issued at 608 PM MST Thu Jan 15 2026

Issued Dense Fog Advisory for both zones in the eastern Magic Valley, as KBYI visibility has gone to 1/4SM. Should last until 18Z/11MST. Will be monitoring for further developments in the Snake River plain.

SHORT TERM /THROUGH SATURDAY/

Issued at 1252 PM MST Thu Jan 15 2026

For the most part, we continue with "wash...rinse...repeat" forecast-wise heading into the weekend. Temperatures are expected to back off a bit with the ridge shifted west a bit and northerly flow over the state vs northwest. Inversions will keep valley temperatures in the 20s and 30s where those hold and pushing back into the 40s where we mix out of staying within the inversion layer. The biggest issue is fog and stratus through tomorrow morning. We did have patchy dense fog around this morning, while at the same time an area of stratus and dense fog pushing back into the Magic Valley from the west. The models are not handling that well, as it SHOULD be stopping forward progress and/or eroding away as of right now...but it hasn't. The winds are light but there is a consistent switch to West or Southwest through tonight across the Magic Valley and Snake Plain. This wind shift is the culprit in driving that back to the east. With that not expected to switch back to an easterly direction until tomorrow, we are thinking it will continue to march slowly east toward Pocatello and Craters of the Moon. The rest of eastern Idaho should see redevelopment of fog and stratus in pockets. We kept stratus in place across portions of the Magic Valley through tomorrow morning, while expanding it elsewhere as forecast by the Blend of Models...which seems reasonable. We are hesitant though to go with anything more pessimistic than patchy dense freezing fog, even with what is happening across the Magic Valley. The higher resolutions have been overdoing the situation the past several nights in most areas. That said, we could see the forecast "busting" especially across the Magic Valley. For tomorrow night, we are not expecting this to be an issue as north to northeast winds SHOULD push all of this back toward Boise and Mountain Home.

LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/

Issued at 1252 PM MST Thu Jan 15 2026

Things look dry until the latter half of next week. The ridge breaks down by then and does allow some moisture work into our area as the flow is more westerly than northerly. Until then, expect more of the same weather-wise. We don't expect the stronger inversions to break until we reach that point in time.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 515 PM MST Thu Jan 15 2026

Stratus and fog continues to move up the Eastern Magic Valley and the lower Snake River plain from the Twin Falls area with southwest winds. Lower visibility has reached BYI and will likely move into PIH in the next couple of hours. There is a small chance that Fog/Stratus could move into SUN before the northwest winds move into the TAF sites. Fog is not that likely at SUN this evening. Fog/Stratus could move into IDA later tonight. However, guidance shows that weak northerly winds will prevail. So, northerly winds would likely keep fog/stratus out of IDA. Though, there is some model guidance that supports some fog and stratus over IDA. If southwest winds prevail for IDA then fog and stratus could move into IDA and continue into the early/mid 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

Dense Fog Advisory until noon MST Friday for IDZ051-055. Air Stagnation Advisory until noon MST Sunday for IDZ054-059.