textproduct: Pocatello

KEY MESSAGES

- Elevated Winds Tomorrow: A Wind Advisory has been issued for Tuesday across the Snake Plain and Arco Desert, where the strongest gusts are expected.

- Mild and Dry Today: High pressure remains in control through this evening, keeping skies largely clear and precipitation chances very low.

- Thunderstorm Potential: Isolated showers and a few thunderstorms are possible Tuesday afternoon, primarily focused east of the I-15 corridor.

- Uncertain Weekend Outlook: While a brief ridge brings mid- week stability, forecast confidence decreases significantly by the weekend as models hint at a shift toward cooler, wetter conditions

DISCUSSION

Issued at 117 PM MDT Mon Apr 6 2026

Afternoon satellite imagery continues to show a lack of any appreciable cloud cover across the region as high pressure remains firmly in control. This tranquil period is nearing its end, however, as a change in the synoptic pattern arrives tomorrow. An upper-level trough is progged to sweep out of Western Canada and dive toward the northern Great Plains and Canadian Prairies. As this feature passes to our north, it will tighten the surface pressure gradient significantly across Eastern Idaho.

The primary impact of this passing trough will be a breezy to windy Tuesday. Model guidance suggests wind speeds will flirt with Advisory criteria for much of the region, and likely exceed it in several zones. Consequently, a Wind Advisory has been issued for the Snake Plain and the Arco Desert, with the latter expected to see the most robust winds throughout the day tomorrow. While areas outside of these designated zones will still experience breezy conditions, speeds are currently forecast to remain below highlight thresholds.

Precipitation chances remain negligible today, generally 15% or less. While high-resolution convective models (CAMs) suggest a stray shower cannot be entirely ruled out near Island Park or Driggs, the probability remains too low for a formal mention in the forecast. Chances increase slightly Tuesday afternoon, particularly for areas east of the I-15 corridor. The environment may be just unstable enough to squeeze out isolated showers or even a few weak thunderstorms. This activity is expected to be hit-or-miss in nature rather than a widespread wetting rain.

Once the trough exits to the east, a brief period of weak ridging will re-establish itself within a broader split-flow regime across the Western United States. This setup should maintain seasonably warm temperatures and generally dry conditions as we approach the weekend. However, forecast confidence begins to erode sharply beyond Friday. Recent model runs have introduced conflicting signals regarding the upper- level pattern, shifting away from the previous dry trend. There has been a noticeable increase in precipitation chances (PoPs) alongside a downward trend in temperatures for Sunday and Monday. Given the volatility in the data over the last 24 hours, the current forecast leans heavily on the National Blend of Models (NBM) until better continuity emerges, though a transition to a more unsettled pattern appears increasingly likely for the start of next week.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1134 AM MDT Mon Apr 6 2026

Weak shortwave moves through East Idaho today, with a few clouds noted today. There is a very low (<10% chance) of a shower developing this evening near or north of DIJ, otherwise dry conditions are expected. A stronger feature moves through Tuesday with cold frontal passage 18-24Z Tuesday. Stronger westerly winds are expected, including SUN, with gusts roughly 20-30kt. IDA, PIH and DIJ may see slightly stronger gusts during the afternoon. DIJ will have the best chance at TSRA during the afternoon.

PIH WATCHES/WARNINGS/ADVISORIES

Wind Advisory from noon to 9 PM MDT Tuesday for IDZ052>054.