textproduct: Pocatello

KEY MESSAGES

- Isolated to scattered thunderstorms this afternoon and evening, then declining coverage on Thursday and Friday.

- Temperatures turn hot again Saturday, a Heat Advisory may be necessary.

- Dry cold front arriving late Saturday should combine with critical fire danger to cause Red Flag conditions.

DISCUSSION

Issued at 1249 PM MDT Wed Jul 29 2026

Showers and thunderstorms developed this morning and continue to move through eastern Idaho this afternoon. By the tonight period, the risk drops strongly, from scattered coverage to mostly isolated by 1800 MDT. The thunderstorm activity has been brought on by a stream of moist and unstable air from the Gulf of California. The upper level wind turns more and more southwest, which will shut off the high moisture content air and the risk of thunderstorms continues to decrease. By Fri afternoon, the upper level flow has shifted completely west and this should end the thunderstorm activity that afternoon. While this is a plus, it does allow the upper level ridge to build into the northern Rockies and the strong sunshine with no clouds will push temperatures to the century mark at lower elevations by Sat. A Heat Advisory may be needed for nearly all low- elevation zones for Sat/Sat Night.

On Sat and Sat night, a dry cold front is expected to approach, then sweep through to the north. There is no precipitation or thunderstorms expected, but the front is close enough to boost wind. Coupled with very low humidity and high fire danger, Red Flag Conditions are expected.

The cold front does bring temperatures down slightly for Sun, and a second cold front on Mon pushes afternoon highs still lower, with afternoon highs in the 80s mainly. The upper level ridge is back by Wed, making for yet another hot, dry spell.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 202 PM MDT Wed Jul 29 2026

Smoke will likely remain an impact at KBYI into the late evening before HRRR smoke model suggests an improvement but this remains to be seen. Maintained VCTS/PROB30s for BYI, IDA, PIH and DIJ to account for thunderstorm and gusty wind potential over the next few hours. Expect VFR conditions and light winds overnight. Another round of isolated showers/storms looks possible for tomorrow but likely with a bit less coverage than what we see today.

FIRE WEATHER

Issued at 202 PM MDT Wed Jul 29 2026

Red Flag Warnings continue across Fire Zones 410, 411, 413 and 427. Models have slowed down by an hour or two on convective initiation across 427, likely due to smoke, coverage limiting instability just a bit but storms in northern Nevada will shift into the area over the next few hours and overspread the rest of zones 410, 413 and 411 into the rest of the afternoon and evening. Lightning and gusty outflow winds upwards of 40-50 mph will be possible in the strongest of storms. Enough moisture lingers across the region tomorrow to support some isolated showers and storms, likely of the drier variety, so gusty winds could be problematic once again.

We quickly dry out starting Friday with very dry air in place heading into next week. The main impact Friday will be increasing HeatRisk impacts for crews. Saturday will be the hottest day, with some mountain locations seeing highs in the 80s to near 90. Valley locations will be in the mid 90s to mid 100s. Winds increase Saturday, with critical fire weather conditions over most areas minus Zone 413 based on the latest forecast. Gusts will be 25-45 mph elsewhere single digit and low teen afternoon humidity. We will a classic ridge breakdown pattern Sunday as low pressure remains to our north, but keeps fairly dry air in place with strong winds expected. Winds exceeding threshold for critical fire weather conditions are likely going to be everywhere with gusts of 25-45 mph once again. Temperatures briefly drop back to around AVERAGE, but warm again next week slowly. Winds will back off a bit, but humidity will remain low, including areas of poor overnight recovery. In fact, a return to poor overnight recovery will likely be a daily issue after tonight.

AIR QUALITY

Issued at 1212 PM MDT Tue Jul 28 2026

Air quality alerts were re-issued for Blaine, Lincoln, Minidoka, and Cassia Counties for the next 24 hours due to proximity and ideal trajectory of smoke from wildfires.

PIH WATCHES/WARNINGS/ADVISORIES

Air Quality Alert until 3 PM MDT Thursday for IDZ051-055>057- 073>075. Air Quality Alert until 3 PM MDT this afternoon for IDZ052- 067>072. Red Flag Warning until 9 PM MDT this evening for IDZ410-411- 413-427.