textproduct: Pocatello

KEY MESSAGES

- Dry weather today, patchy fog overnight tonight.

- Next system arrives Monday night into Tuesday.

- Breezy conditions Monday into Tuesday.

DISCUSSION

Issued at 118 PM MDT Sun Oct 25 2026

High pressure remains positioned over the region today, maintaining dry and quiet conditions into early Monday. Patchy fog developed early this morning and is expected to redevelop tonight into Monday morning under light winds and limited mixing. While locally dense fog occurred earlier today, high- resolution ensemble guidance indicates low confidence in widespread dense fog, with less than a 20% probability of visibilities dropping below 3 miles.

Attention quickly shifts to a fast-moving, relatively shallow Pacific trough dropping into the Pacific Northwest on Monday. Ahead of the boundary, breezy southwest-to-west winds will develop Monday afternoon before precipitation spreads into the central mountains late in the day. Showers will quickly expand across eastern Idaho Monday night as the front pushes through, accompanied by gusty winds. Peak gusts between 30 and 40 mph are anticipated across the Snake River Plain overnight, though winds are expected to remain below Wind Advisory thresholds. QPF guidance remains consistent with previous runs: lower elevations will generally see liquid amounts under 0.10", while mountain zones range from 0.20" to 0.30". The Eastern Magic Valley carries the highest likelihood (>85%) of staying dry, whereas high terrain along the Continental Divide and between I-15 and the Wyoming border has the highest chance (>65%) of exceeding 0.25" liquid. As colder air filters in behind the front, snow levels will fall to around 6,500 feet overnight, yielding 1 to 3 inches of accumulation across mountain passes and peaks, encompassing the vast majority of ensemble spread. While a few stray flakes or a brief rain/snow mix may reach valley floors after midnight, warm surface temperatures will prevent accumulation.

Although the primary shortwave exits rapidly Tuesday afternoon with most lower elevations drying out, eastern Idaho will remain under the influence of a broader trough aloft through midweek. This will support lingering showers across the higher terrain Tuesday afternoon and Wednesday.

Ensemble clusters remain in relatively good agreement regarding the timing and depth of the next Pacific system, despite differences in the shape of the trough along the West Coast. Ensemble means indicate this trough will deepen along the Pacific Northwest coast Thursday into Friday, spreading another round of widespread precipitation, falling temperatures, and high-elevation snow across the region to close the workweek. Given the mean troughing remaining anchored over coastal states, unsettled conditions and scattered shower potential could linger into the upcoming weekend. Precipitation amounts look light at this time. The caveat will be how far off the coast the trough digs, and how much dry southerly flow intrudes into the region before the trough can shift far enough inland.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1041 PM MDT Sun Oct 25 2026

The first 10-14 hours are unlimited CIG and VSBY, but an incoming front changes all that on Mon afternoon. Wind will stop being VRB and taking on a 15G25KT nature by early afternoon, then SHRA will begin in the mid-afternoon, followed by predominating SHRA by late afternoon/early evening. The risk for marginal VFR due to CIG or VSBY are present at KSUN, KIDA and KDIJ. for KIDA, it is due to the risk of BR/FG tonight, where light north wind with limited clouds continues. For the other two, the southerly wind due to the front may push a lot of moisture into the Wood River valley and bring CIG effects to KSUN. KDIJ indicates very little chance of CIG or VSBY problems on the NBM hourly guidance, but time-height cross sections get extremely moist on the NAM. Have tried to split the difference at this airdrome.

FIRE WEATHER

Issued at 105 AM MDT Sun Oct 25 2026

Dry weather is likely today. Another round of precipitation will arrive late Monday and Monday night. Gusty winds are likely on Monday.

PIH WATCHES/WARNINGS/ADVISORIES

None.