textproduct: Pocatello

KEY MESSAGES

- Increasing clouds this afternoon with isolated thunderstorms.

- Wet weather arrives by Saturday for parts of east Idaho.

- Chilly weather over the weekend into early next week.

DISCUSSION

Issued at 200 AM MDT Fri May 29 2026

Closed low will move from the western Great Basin into the eastern Great Basin today. We will increasing clouds this afternoon with dry thunderstorms developing. High res models indicate that the best chances for storms are across the mountains and highlands. These storms should drift northwestward and could possibly move into the Snake Plain and eastern Magic Valley late this afternoon or evening. Another round of stratiform rain move into eastern Idaho from the southeast after midnight as the low enters southwest Wyoming. On Saturday, the low will move northward allowing rain to overspread east Idaho. Precipitation chances fall pretty dramatically from northeast to southwest across our area. For example, areas around Island Park may see up to an inch of rain from this system, while the eastern Magic Valley may not see a drop. Brisk conditions are likely across south Idaho on Saturday and we may meet Lake Wind Advisory criteria for the American Falls Reservoir. Cooler temps will accompany this system with most areas holding in the 60s for highs Saturday and Sunday. The eastern highlands will probably not even get out of the 50s.

This system fully departs the area Monday Night. Overnight lows look very chilly, with upper 30s to around 40 for the Snake River Plain and eastern Magic Valley for Sunday and Monday Night. The pattern returns to a warm and mostly dry zonal flow for the rest of the week. There is some indications that a weak shortwave could pass through around midweek.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 200 AM MDT Fri May 29 2026

Expect increasing mid to high clouds this afternoon. Isolated thunderstorms will most likely not affect TAF sites, probably less than a 20% chance. Widespread rain will arrive late tonight and most likely affect DIJ, IDA, and possibly PIH/SUN.

FIRE WEATHER

Issued at 200 AM MDT Fri May 29 2026

An approaching low pressure system will bring increasing clouds this afternoon. This will produce cooler temps and slightly higher humidity this afternoon. A few isolated dry thunderstorms are possible this afternoon and evening. Gusty erratic winds are possible near storms. Much cooler weather with higher humidity is likely for Saturday. Wetting rains are likely for much of Salmon-Challis and East Idaho on Saturday, but not so much for South Idaho.

PIH WATCHES/WARNINGS/ADVISORIES

None.