textproduct: Pocatello

KEY MESSAGES

- Flood Watch In Effect (TodayMonday): A Flood Watch covers most of eastern Idahoincluding Sun Valley east through the Magic Valley, Snake Plain, and Eastern/Southeastern Highlandsfor a multi-day rainfall event of 1.0 to 2.0 inches, with localized totals closer to 3.0 inches

- Dramatic Weekend Cooldown: Today's upper 70s and 80s mark the final warm day of the season. Highs drop below 70 on Saturday and plummet into the 40s and 50s on Sunday.

- Frost/Freeze Headlines Ahead: Widespread cool temperatures will bring frost/freeze risks starting Sunday morning, becoming more likely Monday through mid-week before headlines are suspended for the season.

DISCUSSION

Issued at 1249 AM MDT Sat Oct 10 2026

Light rain showers/virga have been slowing expanding overnight, and the trend will just continue today. We will see an uptick of precipitation amounts late this morning across the southeast corner, and then most areas outside of the central mountains this afternoon. We do expect thunderstorms today, and there is the potential in addition to some decent downpours, to see some stronger winds. There is a 20-70% chance for gusts over 35 mph, perhaps exceeding 45...IF we can get some stronger storms to fire today. Otherwise, precipitation amounts quickly ramp up starting tonight and continuing through Monday morning. There is still some "wobbling" on where the heaviest amounts will fall, but there is still a pretty wide swath of 1-2" amounts across central and eastern Idaho. It still looks like the "drier" spots will be across Lava Beds where 0.50-1.0" amounts are possible. It also looks like once you get into areas west of US-93 and north of ID-75, 0.30-0.80" is possible. We have widened the area of where we are more likely to see, and have in the official forecast, over 2"...generally east of a line from Monida Pass to around Juniper and Sweetzer Summit. It is likely we will see localized amounts around 3" along and east of I-15. Some of the wobbling is due to the models showing some uncertainty where some of the heaviest bands end up Sunday into Monday. The trend has been to keep split flow, BUT instead of the main closed low being offshore or over California...the trend is shifting northeast toward the Sierras to central Utah. Looking at the higher end of the Blend of Models, we are coming in at or just above the 90th percentile mark in terms of heavier amounts. The absolute highest amounts with the Blend are still running in the 2-4" range...and 4"+ in spots across the eastern and southeast highlands. Those amounts would represent a very, very low probability but higher impact situation. Given the pattern and the influences from Rachel, it is possible we see some isolated high-end amounts. Needless to say, the FLOOD WATCH remains in place. We may need to expand the areal extent into the central mountains depending upon trends in the models, or at least consider watches for the Ohio and/or Wapiti Burn Scars. We must neglect that colder air is going produce some snow at highest elevations of the central mountains and along the Montana border. While we might see a few spots below 8000ft with some brief snow accumulation, that still looks like the lowest we see decent accumulations. We could see over 6" on the highest peaks, 9500-10000ft, and certainly once you get north into Montana where the coldest air will stay.

It will take until Wednesday or Thursday to see low pressure shift east of the Rockies. Lingering showers and cooler temperatures will remain in place through then. High pressure should begin to slowly return later next week. Temperatures will slowly climb back into the 60s for highs in the valleys.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 457 AM MDT Sat Oct 10 2026

Multiple areas of showers/virga continue to push northeast this morning. We are seeing a lull in activity across the central mountains, but should fill back later this morning as the low continues to drop south through the Pacific Northwest. We have see occasional light rain reported, but for the most part we expect sprinkles/virga and will leave VCSH in place (outside of SUN) until this afternoon when coverage everywhere begins to increase. The intensity of thunderstorms on Saturday afternoon remains questionable as temperatures will be dropping by that point, but are still expected isolated to scattered coverage heading into tonight.At this point, mostly VFR conditions will continue, but that becomes less likely as clouds lower and rainfall increases Saturday night into Sunday. We may see more widespread MVFR conditions as we head into this evening and tonight.

FIRE WEATHER

Issued at 1249 AM MDT Sat Oct 10 2026

Showers and thunderstorms slowly expand through the day, with the bulk of the precipitation still expected Sunday into Monday across central and eastern Idaho. Today, while we still have some drier air in place, may see storms with some gusty winds (20-70% for gusts over 35 mph). The trend for widespread 1-2" totals is there over much of central and eastern Idaho. The "drier" spots will be from north of ID-75 and west of US-93 in the central mountains, where 0.30-0.80" is still possible. The other main area of lower amounts is west of US 93 across the Magic Valley where 0.50-1.0" is possible. We are still expecting amounts in excess of 2" in some spots along and east of I-15...trying to approach 3" locally. The higher end of the Blend still is trying to paint widespread 1.5-3.0" amounts, locally push 3.5"...and the absolute highest in the 2-4" range areawide with places in excess of 4". The higher end amounts are certainly a possibility due to pattern and strong influence from Rachel. Snowfall is still confined to above 8000ft in the central mountains and along the Montana border. It is possible we could see brief snowfall/accumulation in colder basins, though. Showers will linger through midweek as low pressure will be slow to move into the Plains, although expect much less precipitation after Monday. High pressure looks to rebuild late next week, with a slow warming trend currently forecast.

PIH WATCHES/WARNINGS/ADVISORIES

Flood Watch from noon MDT today through Monday afternoon for IDZ051>067-073-075.