textproduct: Pocatello

KEY MESSAGES

- Warm Holiday Weekend: Temperatures will quickly rise into the 70s and 80s through Monday. Memorial Day will be the warmest day of the stretch, with lower elevations reaching the mid-to- upper 80s.

- Isolated Showers & Virga: Highs will pair with low-end shower chances today, though dry air means mostly virga. Precipitation chances increase slightly Sunday near the Utah/Wyoming borders before shifting to the central mountains on Memorial Day.

- Mid-Week Pattern Shift: A closed low pressure system arrives Tuesday and lingers through late next week, bringing cooler, more seasonal temperatures in the 60s and 70s alongside daily rain and thunderstorm chances.

DISCUSSION

Issued at 144 PM MDT Sat May 23 2026

Warm temperatures and the potential for isolated showers and thunderstorms will characterize the upcoming holiday weekend across eastern Idaho. Afternoon satellite imagery shows a gradual expansion of a cumulus field, particularly over the higher terrain, though local radars remain clear of any significant precipitation. High-resolution model guidance indicates a 10% to 20% chance of light showers or sprinkles passing through the region this afternoon. Because dry air remains entrenched at the surface, these showers will primarily result in dry virga, though a very low possibility of an isolated thunderstorm remains. Wind gusts are expected to remain quiet today, with a minimal chance of exceeding 35 mph.

For Sunday, precipitation chances pick up slightly. Guidance highlights around a 30% chance for showers and thunderstorms south of the Snake Riverfocusing primarily near the Utah and Wyoming bordersand a 10% to 30% chance across portions of the central mountains and eastern highlands. On Memorial Day, the primary focus for isolated activity shifts back into the central mountains. Underneath these passing cloud decks, a steady warming trend will carry afternoon highs well into the 70s and 80s, making for a seasonably warm holiday weekend. Lower valley locations will peak on Monday afternoon, with highs topping out in the mid-to-upper 80s.

The tranquil, warm pattern begins to break down on Tuesday as a closed low pressure system moves into the western U.S. and meanders into the Great Basin. This system is forecast to remain in place through the middle and latter portions of next week, keeping conditions unsettled across the region. Consequently, daytime highs will trend cooler, dropping back into the more seasonal 60s and 70s. Daily chances for showers and thunderstorms will return to round out the month of May. Depending on the eventual placement and track of the upper-level low, we could also experience some breezier days during the mid- week timeframe.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 522 PM MDT Sat May 23 2026

VFR conditions forecast through the period with high clouds. Winds will continue to subside this evening but will increase again tomorrow afternoon with widespread gusts 15 to 25 kts. Showers and thunderstorms tomorrow afternoon will favor areas south of the Snake River Plain with thunderstorms largely expected to remain away from the terminals. Probability of thunder tomorrow afternoon will range 20 to 30% at KBYI and KDIJ, with less than 20 percent chance elsewhere. Therefore, have included a PROB30 at the two aforementioned terminals with confidence too low elsewhere for any mention in the forecast.

FIRE WEATHER

Issued at 1248 AM MDT Sat May 23 2026

Warmer temperatures will lock in for the Memorial Day Weekend, with highs in the 70s and 80s. We are not seeing any major drop in humidity at this point though. Mid level moisture sticks around for a lower end chance of light rain showers/sprinkles and a few thunderstorms. There is a 10-20% chance today across Zones 411, 422, 427, and 476. We could see something develop across the north end of 410 along outflow boundaries. The potential increases on Sunday especially across 413 and 427. A secondary area will develop from around Mackay (476) eastward toward Driggs (410 and 411). There is a 10-30% chance of gusts over 35 mph with the northern swath, and 30-50% down south closer to the Utah border. For Memorial Day, as low pressure swings inland, we will see another small increase in showers and thunderstorms especially over the central mountains. As quickly as we go to ABOVE AVERAGE temperatures, we will swing back to AVERAGE to BELOW AVERAGE temperatures. A closed low will take a few days to move across Idaho, but in the process we do expect an increase in the potential for showers and thunderstorms.

PIH WATCHES/WARNINGS/ADVISORIES

None.