textproduct: Pocatello

KEY MESSAGES

- Showers and thunderstorms continue into the weekend as monsoon moisture remains in place

- Deeper surge related to Tropical Storm Iselle arrives for Friday and Saturday

- Drier Conditions MAY move in for early next week

DISCUSSION

Issued at 110 PM MDT Wed Aug 26 2026

Monsoon moisture will remain in place at least through the upcoming weekend. We have already seem some light showers/virga this morning with an overnight surge of moisture. This will limit thunderstorm coverage through this evening in some areas due to early cloud cover. That said, we do expect an increase in coverage with the better chances behind the current activity over the central mountains and higher terrain south of the Snake Plain and Magic Valley. We will likely see more isolated storms elsewhere, and potential issues with outflow boundaries and possible storms along those across the Magic Valley and Snake Plain. There is a 30-80% chance for gusts over 35 mph and pushing 50-60mph with select storms/boundaries through midnight. We do expect a few showers/virga across the central mountains and moving into the Magic Valley tonight. There could be a lightning strike or two, but the potential is well under 10%. Most storms will not produce much if any measurable rain, but stronger storms may indeed produce locally heavy downpours and small hail. We will see the usual uptick tomorrow afternoon and evening, with activity more widespread across central and eastern Idaho. The nature of storms tomorrow will be similar to today and the past several days. For Friday and Saturday, the latest trends bring a big surge of moisture into Idaho as the monsoon pattern picks up moisture from Tropical Storm Iselle. This is expected to finally clear our area by later Sunday. The current Blend of Models forecast wants to focus higher precipitation totals across the eastern and southeastern highlands, but that may be too confined. We will need to watch to see if the deepest moisture is spread farther west, and enhanced by thunderstorms. There is moderate to high potential for more than 0.50" in each 24 hour period, and lower end potential for over 1.00" in each 24 hour period. Afternoon temperatures drops from the 80s and lower 90s to 70s (maybe some upper 60s around) during this stretch.

Both the ECMWF and GFS point toward breezy and drier conditions for the first part of next week. More than one low passes through to our north, and tries to push the monsoon surge east of us. The Blend of Models is not as optimistic and keep some chance of showers and storms around.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1154 AM MDT Wed Aug 26 2026

No major changes in the TAF with this issuance. Once again we expect afternoon showers and thunderstorms around the area with potential impacts at our terminals. Showers and storms may stay out of IDA completely, remaining north. Unless a terminal takes a "direct hit" from a storm, expect VFR conditions. Winds remain light and variable outside of thunderstorms, which could gust to around 50 mph again. Some of our short-range models are showing showers tomorrow morning, so have added VCSH to the TAFs, but confidence is low.

FIRE WEATHER

Issued at 110 PM MDT Wed Aug 26 2026

Monsoon moisture continues into Eastern Idaho as it works up and around high pressure over the Southwestern US. Isolated thunderstorms are still the name of the game this afternoon and we continue this trend again tomorrow. Things begin to change on Friday as an area of low pressure drops southward into southern British Columbia. This will help funnel some Pacific moisture to our area and looks to bring some actual rainfall to the area compared to our mostly dry thunderstorms as of late. A cold front will also come through the area and drop our highs into the 70s for many this weekend. On Saturday, expect more widespread scattered thunderstorm activity, though these storms will be wet. From Friday through Sunday, many of our higher elevations will likely see somewhere between a quarter to a half inch of precipitation. At the lower elevations, we will be looking at a tenth to a quarter of an inch. Though we will take any precipitation we can get.

PIH WATCHES/WARNINGS/ADVISORIES

None.