textproduct: Pocatello

KEY MESSAGES

- Above average temperatures continue into next week

- Wet and windy conditions return starting Monday

- Low confidence in patchy freezing fog tonight

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 1144 AM MST Fri Dec 12 2025

The weather heading into the weekend will be much calmer that recent days. We really haven't much in the way of precipitation around Island Park and the latest forecast trends confirm that. That means it should dry until we get into early next week. Two things to note in the forecast. The first is the persistent warm pattern remains in place not only through the weekend, but well into next week even with changes coming by then. We are starting off a bit cooler overall and that has put us a bit cooler for this afternoon. That said, Challis already set a record for today. Our other official climate sites likely will fall short today of even being close because of this trend. We do cool off a bit tomorrow likely due to the ridge starting to shift over us and seeing weak inversions. Even then, we are still running 10-20 degrees above average. The other thing to watch is for patchy freezing fog tonight. We didn't see anything like that this morning, and looking at the HREF and REFS models...that was to be expected. Those higher resolution models do up the ante, so to speak, across the INL through north of Idaho Falls into Island Park and toward Monida Pass. The probability is highest in the REFS at 30-60 percent. We had that already in the forecast for tonight, as we will leave it in for now. If we don't any real sign of it forming by mid-evening, we may need to remove it from the forecast.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 1144 AM MST Fri Dec 12 2025

Mild northwest flow pattern continues for the foreseeable future. Valley daytime highs remain well above normal for this time of year, and overnight lows are close to the normal highs. We do see the ridge begin to shift east Monday with onset of precipitation across the region Monday night into Tuesday. Clusters this morning are similar on timing of the breakdown and arrival of precipitation and wind into East Idaho for midweek. Precipitation appears focused for the higher elevations of East Idaho, particularly the western edges of the central mountain zones and along the Wyoming border. Snow levels remain high as the system arrives, but do weaken through the day Wednesday with progression of a cold front through the region. Temperatures do lower Tuesday into Wednesday, but remain warm at lower levels so any precipitation that does fall through the Snake Plain will likely remain rain, at least until Wednesday night as overnight lows approach freezing. Unsettled and mild conditions continue through the end of the week and forecast period with another feature bringing mainly higher elevation snow.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 548 PM MST Fri Dec 12 2025

High pressure continues for at least the next 24 hours. Nearly clear skies is allowing vertical mixing that will produce gusty wind at KPIH and KIDA. Only KDIJ has a CIG, and that is limited to this evening. Otherwise only cirriform cloudiness and limited to FEW-SCT. Wind stays light at all the other airdromes.

PIH WATCHES/WARNINGS/ADVISORIES

None.