textproduct: Pocatello

KEY MESSAGES

- Breezy Conditions: Wind Advisory today for the Snake River Plain, eastern Magic Valley, Arco Desert, and Shoshone area for sustained winds 25 to 35 mph and gusts to 50 mph.

- Another Drastic Temperature Swing Coming: Temperatures tomorrow will struggle to reach the mid-40s to mid-50s.

- Frost and Freeze Risk: Freeze Warning in effect for our growing zones tonight, with hard freeze possible in areas. Similar temperatures are expected Monday and Tuesday mornings.

DISCUSSION

Issued at 128 PM MDT Sat May 16 2026

Satellite water vapor imagery this afternoon reveals a broad, shallow trough axis shifting across the Pacific Northwest, with a distinct shortwave axis pushing through east Idaho ahead of the parent circulation center over central Washington. Under extensive cloud cover, unseasonably cool temperatures remain entrenched across the region today. A few light showers are possible through this evening, primarily restricted to zones bordering southwest Montana where precipitation amounts will be heavily limited. Model guidance is in good agreement that the main circulation center will track southward from Washington into northern Nevada overnight into early Sunday morning. While gusty daytime winds will ease over the lower elevations tonight, cold air will settle into the region as the upper core shifts overhead. A WIND ADVISORY remains in place today, with the strongest winds across the Arco Desert.

High confidence of freezing temperatures continues overnight tonight, and the FREEZE WATCH has been upgraded to a FREEZE WARNING for the entirety of the Snake Plain. For a large portion of the warning area, low temperatures will bottom out between 27-32 degrees. However, probabilistic ensembles suggest a 40-60% chance that localized areas from Craters of the Moon northeastward to Mud Lake could experience a hard freeze at or below 28 degrees. Along the interstate corridor between Burley, Pocatello, and Idaho Falls, overnight lows remain marginally above freezing, limiting the potential for freeze although frost will still be possible. On Sunday, a tightened northerly surface pressure gradient will overspread the region. This will elevate wind speeds sufficiently to warrant a LAKE WIND ADVISORY for the American Falls Reservoir, where choppy water is expected to increase near the dam.

Unsettled weather will linger over the higher terrain tonight into Sunday, but the most cohesive period for widespread precipitation arrives late Sunday night into Monday morning. As the upper low migrates eastward through Utah, overrunning moisture will interact with the cold air mass, supporting a transition to snow down to valley floors across the southern and southeastern highlands. Total snow accumulations of 2 to 6 inches are expected across the Bear River Range and areas stretching east to the Wyoming border, with generally less than an inch elsewhere. Sub-freezing overnight lows will persist through Tuesday morning, making additional frost and freeze headlines highly likely for early next week. Ensemble solutions continue to struggle with the details in the slowly departing trough. Occasional mainly higher elevation showers remain possible through the week, but the overall trend still supports temperatures moderating through the week. Overnight lows should recover above freezing for most areas for Wednesday morning and beyond.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1125 AM MDT Sat May 16 2026

Wind continues to be the biggest impact at our sites today with afternoon gusts to 20-25 kts at SUN and DIJ and 25-35 kts at BYI, PIH, and IDA. This comes as a trough is moving into the area today and passing directly through on Sunday and Monday. Cloud cover has been on the increase as a result, and while there is a very small (10-15%) chance of a few sprinkles at DIJ this afternoon, the probability is not high enough to put into the TAF at this time. Precipitation chances will increase for SUN and DIJ on Sunday as the trough really begins drop southward into eastern Idaho as we remain breezy.

PIH WATCHES/WARNINGS/ADVISORIES

Wind Advisory until 10 PM MDT this evening for IDZ051>055. Freeze Warning from 3 AM to 9 AM MDT Sunday for IDZ051>055.