textproduct: Pocatello

KEY MESSAGES

- Warming trend through Thursday will drive down afternoon humidity readings to critical fire weather levels at lower elevations.

- Approaching trough will increase wind on Thursday and Friday to critical fire weather levels. Red Flag Warning may be needed Thursday.

- Showers and thunderstorms may arrive as early as late Thursday night/Friday morning in the southern and eastern highlands.

DISCUSSION

Issued at 104 AM MDT Wed Sep 9 2026

Today through Fri night...High pressure slowly breaks down in advance of an incoming trough during this period, starting Thursday. Until then, expect sunny skies and temperatures returning in lower elevation to above 80 deg F starting today, and even warmer Thu. The approaching trough brings cooler air and cloud cover, and temperatures will start to cool from Thu to Fri. There is a very weak chance of precpitation, mainly seen on ECMWF model runs, for the southern and eastern highlands, spilling into the Snake River plain.

Wind will be light today, but on Thu afternoon, as the trough draws closer, will increase substantially, with windy conditions (20 to 30 mph with gusts to 40 mph) developing. Wind will continue to be at that level Fri afternoon.

Sat through Tue...The trough that brings the wind and a slight chance of showers and thunder on Thu night/Fri will cross over the forecast area. This will increase the threat of showers and thunderstorms, which will bring significant cooling after the trough passes to the east on Sat night. Temperatures will cool by 15 to 20 deg F for afternoon highs.

Wind will weaken on Sat, then increase again on Sun in the post trough regime. Mon will see the departure of the trough's influence, with temperatures starting a warming or at least bottoming out, with once again nearly clear skies and a return to dry conditions for Mon to the end of the forecast period. Temperatures will warm back to near normal by Tue/Wed.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 454 AM MDT Wed Sep 9 2026

No clouds, no restrictions to VSBY under high pressure. Wind shifts are the only significant forecast, with only 15KT being reached at KSUN. Wind tonight is not as light and variable due to a trough starting to influence wind on Thursday.

FIRE WEATHER

Issued at 104 AM MDT Wed Sep 9 2026

A drying out as temperatures warm will push widespread afternooon humidity readings at lower elevations below the 15 percent critical criteria. This will not be so bad today, as wind will be remaining light; however an approaching low will increase the wind so that G25KT to G40KT will be likely for Thu and Fri. This makes an overlap day of gusty wind and very dry conditions occur on Thu. The low will start cooling temperatures, mainly in the west, on Fri, along with bringing in higher humidity air. So Fri is likely only to see critical fire weather condtions in the eastern portions, if fuels meet critical levels still. Afternoon temperatures will cool by Sun into the 50s and 60s, ending the critical humidity threat, even if Sun returns to being wind like Thu and Fri. Warming and drying return on Mon, with wind staying light as this is caused by high pressure returning.

PIH WATCHES/WARNINGS/ADVISORIES

None.