320 FXUS65 KPIH 011718 AFDPIHArea Forecast Discussion National Weather Service Pocatello ID 1118 AM MDT Wed Oct 1 2025
...UPDATED AVIATION...
.KEY MESSAGES...
- Showers and storm will persist, but less numerous through Thursday
- Temperatures briefly warm up
- Showers, storms and much colder temperatures heading into the weekend
&&
.SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 1215 AM MDT Wed Oct 1 2025
Unsettled weather is expected to continue over the next couple days. We`re in southwest flow ahead of deep upper level trough. Isolated to scattered showers and thunderstorms will move through our region in this flow. Although we`re not looking at anything organized. As we move into Thursday and especially Thursday night a cold front and associated low pressure system will approach the region from the west-southwest. Ahead of this system during the day on Thursday, the central mountains will see numerous showers throughout the day. The rainfall will become heavier Thursday Night as the low pressure system and cold front move into southwest Idaho. During the day on Thursday the rainfall will still likely be light with amounts expected to be between 0.10 to 0.25 inches in the central mountains. Across the rest of central and east Idaho, activity will remain isolated to scattered with amounts expected to be less than 0.10 inches. As we move into Thursday Night, rainfall amounts in the central mountains could exceed 0.50 inches perhaps approaching 1 inch, perhaps resulting in issues for the Wapiti burn scar. For the rest of central and east Idaho, latest guidance indicates the cold front will not arrive until Friday so rainfall amounts Thursday night for central and east Idaho will most likely be light and less than 0.10 inches.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/... Issued at 1247 PM MDT Tue Sep 30 2025
The next big chance of precipitation and thunderstorms is Thursday night through Saturday evening. With split flow continuing over the western states, the next storm will be undergoing this change as it moves inland. The current trends will initially take the closed low/southern end of the split to our southwest, and then swing it northeast across Utah and western Wyoming going into Saturday. The current pattern shows Thursday night into Friday with a band of heavier precipitation across portions of the Magic Valley and central mountains, not that different that what occurred last night. That band stays in place, and eventually shifts when the storm crosses through and east of the Divide. If current trends hold, this is a pattern for heavier precipitation due to wraparound and upslope along and east of the I-15 corridor. There is a MARGINAL RISK for excessive rainfall Thursday night across the central mountains. While it is certainly possible we could see some debris flow issues, the risk is lower at the moment. With a colder system moving in, that does mean some wet, slushy snow is possible on higher peaks and ridges. Forecast snow levels are currently getting down to around 8000-8500ft in the central mountains and ~9000ft across the southeast highlands. If we can maintain heavier amounts or end up with colder temperatures, there is potential for snow levels to PERHAPS drop between 6500-8000ft areawide...according to the Blend of Models snow level forecasts. That doesn`t necessarily we would see a bunch of accumulation at those elevations, but we could easily snowflakes in the sky and melting as they hit the ground. Right on the heels of this low, another drops down into the western U.S., and does a similar thing with another split flow system developing. Even if we see less precipitation with that one, it will maintain cooler temperatures across the state. Highs over the weekend based on the current Blend of Models forecast barely touch 60 degrees in the valleys with 30s and 40s for anyone wanting to take a trip to the high country!
&&
.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1115 AM MDT Wed Oct 1 2025
We will see showers and a few storms around through tomorrow. Unless a stronger shower or storm pops up directly over any particular TAF site, look for VFR weather. The only airport we have VCSH in for is SUN and that has been continued from the previous set of forecasts. Due to limited coverage, we removed any mention for other TAFs. Right now, coverage and/or confidence is too low to even include PROB30.
&&
.FIRE WEATHER... Issued at 1215 AM MDT Wed Oct 1 2025
Unsettled weather will continue through Thursday with isolated to scattered showers and thunderstorms. Rainfall amounts expected to be light, less than 0.10 inches. A few wind gusts of 15 to 20 mph will remain possible each afternoon. A more organized system will arrive Thursday night and Friday resulting in better chances for wetting rains.
&&
.PIH WATCHES/WARNINGS/ADVISORIES... None.
&&
$$
SHORT TERM...13 LONG TERM...Keyes AVIATION...Keyes FIRE WEATHER...13
NWS PIH Office Area Forecast Discussion