textproduct: Pocatello

KEY MESSAGES

- Increasing winds this afternoon with near-critical to critical fire weather conditions

- A few sprinkles/virga with gusts over 35 mph possible this afternoon and evening

- Rain and mountain snow increases tomorrow and continues through Monday

DISCUSSION

Issued at 1145 PM MDT Thu Oct 8 2026

Our major pattern shift begins today as low pressure begins to drops across western Canada. This will produce gusty winds across a good chunk of eastern Idaho. Gusts in the 25-35 mph are expected, with some gusts closer to 40 mph across the central mountains. We should also see some mid level clouds developing the area this afternoon. The concern isn't necessarily rain, as it should be way too dry to get measurable rain at least initially. The concern is sprinkles/virga and enhance wind gusts. There is a 10-50% chance for gusts over 35 mph for late afternoon into the evening hours. While the chance is extremely low, we might even see a couple of thunderstorms. Overnight, we do expect a slow uptick in the potential for trace rainfall amounts or may a couple of hundredths worth of rain, mainly across higher elevations. Temperatures will actually be a bit warmer today especially where we might get a little bit of help from downslope. That said, it still will be in the mid 70s to mid 80s for the valley. We can say goodbye to those temperatures for a bit after today.

Showers and storms will begin to increase tomorrow fairly quickly once we get later in the day. By tomorrow night and lasting into Monday, more widespread rain and mountain snow is likely with some embedded thunderstorms. The pattern, although showing some minor shifts across the western U.S. still develops a strong closed low across California, as the flow splits. The northern end of the split maintains a slow moving through extending through western and central Idaho and north into Canada. We are staying on the warm side of the storm through Monday. This is helping keep mountain snowfall potential north across Montana except for the trough/area of low pressure across central Idaho and around Island Park. The pattern also holds taking the remnants of Rachel all the way north into Utah, Wyoming and Idaho. We continue to refine and increase precipitation amounts, as it does appear there is still a shift to the west with heavier precipitation. The latest forecast has more widespread amounts of 1-2" now back across the Snake Plain and into the central mountains from the Wood River Valley through the southeast corner of Lemhi County. There is still some expectation we could see totals above 2" along and east of I-15. Even where we may not see 1"+ precipitation amounts across the central mountains, totals are still running 0.40-0.90". If you look at the higher end of the Blend of Model rainfall totals, it is showing widespread 1.5-3.0"...highest across the same strip of the central mountains as well as the eastern and southeast highlands. The absolute highest in the Blend is coming in at 2.0-3.5" and locally higher near 4" in a few spots. While the absolute highest have a very low chance of occurring, some areas seeing amounts of 2-3" is definitely out of the question.Based on the current trends accumulating snow is confined to mostly above 8000ft now. Light amounts are still expected, but highest peak and ridgelines may indeed several inches of wet snow accumulation across the central mountains and along the Montana border.

Low pressure remains across the region through midweek, so do expect show showers to stick around along with those cooler temperatures. Most versions of the GFS and ECMWF (including ensembles) show high pressure redeveloping across the West later next week.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1158 AM MDT Fri Oct 9 2026

After a long period of light winds and clear skies, conditions begin to turn starting this afternoon. Winds increase across the region, peaking around 15kts sustained with gusts around 25kts. They decrease slightly overnight, but pick up again Saturday morning. SUN should experience normal diurnal down-valley winds this evening, but the incoming upper low is expected to turn SUN winds southerly or southwesterly around sunrise. Cloud cover increases into tonight as moisture deepens across East Idaho, but VFR is still expected. PIH, IDA and DIJ could see a few SHRA by sunrise, but DIJ has the better chances of precipitation after sunrise and will carry PROB30.

FIRE WEATHER

Issued at 1145 PM MDT Thu Oct 8 2026

Our pattern shift starts today, in the form of stronger wind and increasing mid level clouds. We are expecting gusts in the 25-35 mph range to be pretty common by this afternoon, with some gusts closer to 40 mph in the central mountains. Humidity does come up a bit in the central mountains and the far southeast corner, expect pretty dry air to remain in place today. We will maintain a RED FLAG WARNING for Zone 427 due to drier fuels and stronger gusts. With the mid level clouds developing later today, we are may actually see some virga or sprinkles and enhanced gusty winds. We did add isolated "showers" mainly over higher terrain, although it does appear some measurable rain is possible across portions of the central mountains overnight. The potential for gusts over 35 mph is 10-50% for areas outside of the central mountains.

Starting tomorrow and through Monday, showers and embedded thunderstorms become more widespread. The trend has been to bring higher rainfall totals as far west as from the Wood River Valley through southeast Lemhi County, and points east from there. Snowfall is still possible across the central mountains and along the Montana border, but accumulations are really limited above 8000' and higher. Precipitation totals across Zone 475 and the Stanley end of 422 are currently running at 0.35-0.90", as well as the west of U.S 93 across the Magic Valley. Otherwise, more widespread 1-2" totals are now in the forecast, with some pockets over 2" along and east of I-15. The higher end of the Blend of Models forecast has widespread 1.5-3.0", with absolute highest totals hitting 2.0-3.5" with a few spots closer to 4". While these highest end amounts have a extremely low chance of occurring, it is plausible given the influence from Rachel.

PIH WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 8 PM MDT this evening for IDZ427.