textproduct: Pocatello

KEY MESSAGES

- Red Flag Warning in effect this afternoon and evening for Fire Weather Zone 427 (South portion of Sawtooth NF) for low humidity and gusty wind.

- Windy Sunday for portions of the Upper Snake River Plain. A Wind Advisory is in effect.

- Temperatures cool 10-15 degrees into Monday, then warm through the remainder of the week.

- Quite a bit of uncertainty into the end of the week regarding precipitation potential.

DISCUSSION

Issued at 210 PM MDT Sat Sep 12 2026

Satellite imagery shows closed low centered off PacNW coast today with shallow ridge in place over East Idaho. Combination of gusty winds in a few areas and still-low humidities has implications for fire weather concerns today. See that discussion below. Shortwaves ejecting northeast out of southern Oregon today expected to cross the region overnight tonight. Trajectory of deepest moisture shifts mainly through western Idaho into the panhandle overnight, with only a very small portion of the central mountains seeing any potential of precipitation. Most of East Idaho will remain dry with this feature. The main impact will be twofold: winds Sunday and ushering cooler temperatures by Monday. Have issued a WIND ADVISORY for the Arco/Mud Lake/Dubois region Sunday (Zones 52 and 67). NBM currently showing a greater than 80% probability of wind gusts exceeding 45 mph across the region but a less than 40% probability of gusts exceeding 50 mph. Temperatures cool Sunday, but the greatest drop in daytime highs arrives Monday, well behind the front. Daytime highs are generally expected to be in the 60s for most of the East Idaho population.

For the rest of the week, ensemble clusters have transitioned to keeping Idaho under the influence of a weak trough for the first half of the week with a split flow pattern shifting inland off the Pacific for the latter half of the week. The clusters are showing a lot of disagreement. NBM shows precipitation across portions of East Idaho by Thursday. Temperatures are expected to rebound back to slightly above normal through the end of the week.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1115 AM MDT Sat Sep 12 2026

VFR conditions expected to continue with 10 to 15 knot winds expected today after 18Z at all sites. Much stronger winds are expected Sunday and after 12Z increased to 10 to 15 knots sustained with gusts 25 to 30 knots at the 4 of the 5 sites. Delayed until after 18Z at SUN. Not expecting any cloud cover other than scattered to broken above 10 thousand feet.

FIRE WEATHER

Issued at 210 PM MDT Sat Sep 12 2026

Main impact through Sunday will be strong winds. Have the red flag warning in effect for zone 427 through 9 pm this evening. Do expect widespread wind gusts Sunday in the 20 to 35 mph range, but will not have widespread humidity below 15 percent. Think those levels will be very limited so no warnings in effect Sunday. Winds die down substantially late Sunday afternoon into next week. Will see very cool conditions Monday but the cool down will be very limited with ridging building back in next week. By Tuesday above normal temperatures will return. Mainly dry conditions are expected through next week with the best chance Thursday for precipiation mainly in zones 411 and 413.

PIH WATCHES/WARNINGS/ADVISORIES

Wind Advisory from 11 AM to 7 PM MDT Sunday for IDZ052-067. Red Flag Warning until 9 PM MDT this evening for IDZ427.