textproduct: Pocatello

KEY MESSAGES

- Fog/Stratus Return Possible Tonight: Morning low stratus is gradually eroding this afternoon, though lingering low-level moisture over saturated soils may support the redevelopment of low stratus and patchy fog tonight into Tuesday morning.

- Chilly & Stagnant Workweek Temperatures: Daytime highs will remain suppressed in the 40s today due to persistent low clouds. Temperatures will remain generally stagnant with minimal day-to-day fluctuations through Friday.

- Weak Mid-to-Late Week Impulses: Dry conditions prevail across eastern Idaho, though a series of weak upper-level impulses will bring periodic cloud cover and low-end precipitation chances mid-to-late week with no major weather systems expected.

- Building Weekend Ridge & Above-Normal Warmth: Global models remain steadfast in building and strengthening an upper-level ridge directly over the region this weekend, ensuring dry weather and driving temperatures to above-normal levels late this weekend into next week.

DISCUSSION

Issued at 145 PM MST Mon Nov 2 2026

Afternoon satellite imagery reveals a gradual erosion of the low stratus deck that lingered across much of the area through the morning hours. Extensive morning cloud cover severely hindered diurnal warming, keeping temperatures unseasonably cool with much of the region remaining in the 40s this afternoon.

With precipitation having fully exited eastern Idaho, the primary short-term operational concern shifts to nighttime boundary-layer evolution. While confidence in complete boundary- layer decoupling remains moderate, abundant residual low-level moisture makes the redevelopment of low stratus and patchy fog probable overnight into Tuesday morning. Areas that see sustained clearing around sunset will have the highest likelihood of seeing fog formation before boundary-layer mixing resumes Tuesday afternoon.

A tranquil and predominantly dry pattern will dominate the remainder of the workweek. Operational guidance continues to track a series of weak upper-level impulses crossing the region mid-to-late week late tomorrow and again Thursday PM into Friday AM. These disturbances will periodically increase cloud cover and could generate isolated, low-end precipitation chances over the mountains, but dynamic lift is weak and no organized, impactful storm systems are expected. Temperature profiles will remain largely stagnant day-to-day through Friday, with afternoon highs continuing near or slightly below late-autumn climatology.

Medium-range model guidance remains in strong consensus regarding a pronounced pattern change heading into the upcoming weekend. Ensembles are steadfast in building and amplifying an upper-level ridge directly over the Intermountain West. Strong subsidence beneath the ridge will maintain completely dry conditions across eastern Idaho, while rising 500 mb heights initiate a steady warming trend. Daytime maximum temperatures will rebound to above-normal levels starting late this weekend and likely holding into early next week.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 353 PM MST Mon Nov 2 2026

The primary challenge then shifts to overnight redevelopment. With abundant boundary layer moisture from recent rainfall, decoupling winds, and clearing skies aloft, high-res guidance and model soundings strongly favor fog and low stratus development tonight. The greatest potential resides along the southern and eastern periphery of the Snake River Plain and into the Teton Valley. Introduced prevailing MVFR visibilities with VCFG mentions after 06Z-09Z for BYI, PIH, IDA, and DIJ, with localized IFR/LIFR restrictions possible towards daybreak. We did stick in some lower clouds at BYI as there is some hint that some fog or low clouds develop and get pushed back toward Boise. SUN was cautiously kept VFR overnight, banking on nocturnal downvalley northerly flow to keep the moisture pushed southward...and stratus that exists in the Magic Valley dissipates before getting caught up in afternoon upvalley wind shift. We should see VFR conditions at all sites by tomorrow afternoon.

FIRE WEATHER

Issued at 134 AM MST Mon Nov 2 2026

Cold temperatures and high humidity will continue through at least Tue. High pressure will allow more significant lowering of humidity on Tue afternoon/Wed. Conditions should become dry after today with no precipitation expected until possibly late in the upcoming weekend. Stratus and fog will be affecting areas both tonight and Tue night. Gusty wind today in the Southern Idaho Dispatch area will decrease during the afternoon.

PIH WATCHES/WARNINGS/ADVISORIES

None.