094
FXUS65 KPIH 291751
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1151 AM MDT Fri May 29 2026

.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 /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1145 AM MDT Fri May 29 2026

A low pressure system currently to our south will keep the pattern
active throughout the weekend. Have forecast PROB30s for -tsra this
afternoon at all sites except for KSUN. The closed low will begin
tracking northward early Saturday morning, resulting in
precipitation chances increasing from east to west. Showery
precipitation overnight will turn more persistent at KPIH, KIDA, and
KDIJ as the low works northward and wraparound moisture brings the
most organized precipitation to the terminals. The best chances of
precipitation will be north and east of KPIH. CIGs and VIS will
remain VFR at KBYI and KSUN while CIGs will trend low VFR to MVFR
Saturday morning at KPIH, KIDA, and KDIJ. Model guidance suggests
VIS impacts down to IFR at KDIJ in moderate to heavy rain during the
early morning. Westerly winds will also increase today into Saturday
with the strongest gusts peaking at around 30 kts early Saturday at
KPIH and KBYI.

&&

.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.

&&

$$

DISCUSSION...13
AVIATION...Cropp
FIRE WEATHER...13