textproduct: Pocatello

KEY MESSAGES

- Severe Wind Threat Today: The Storm Prediction Center (SPC) has placed the extreme southern tier of the areaspecifically the higher terrain of the South Hills, Albion Mountains, and areas near the Utah borderunder a Marginal Risk for severe storms today. High-based virga showers will be capable of generating sudden, localized dry microburst with gusts up to 55 mph possible.

- Mid-Week Dry Thunderstorms: Mid-level moisture expands across Eastern Idaho today and Thursday. Isolated to scattered high- based thunderstorms will pose a dual threat of dry lightning ignitions and erratic wind outflows exceeding 35 to 55 mph.

- Late-Week Wind Surge: Widespread gradient winds will ramp up slightly mid-week before jumping dramatically on Friday ahead of an approaching storm system. Widespread gusts of 20 to 40 mph may necessitate wind headlines for portions of eastern Idaho.

- Late-June Cooldown: An unusually potent early-summer low- pressure system arrives this weekend. Sunday will be the coldest day of the stretch while Saturday features widespread wetting rains, high-elevation mountain snow, and afternoon max temperatures plunging into the 50s and lower 60sroughly 20 degrees below normal. Record Low Max Temperatures possible on Sunday.

DISCUSSION

Issued at 213 AM MDT Wed Jun 24 2026

The overarching synoptic pattern through Friday will be defined by a steady surge of mid-level moisture tracking through a fast, dry zonal flow overhead. This profile will support widespread high-based virga and light showers today, transitioning into an active dry thunderstorm setup beginning this afternoon and continuing through Friday.

For this afternoon and evening, the Storm Prediction Center (SPC) has highlighted the extreme southern tier of the forecast areaincluding the higher terrain of the South Hills, Albion Mountains, and locations directly along the Utah borderin a Marginal Risk for severe weather. Driven by a deeply dried sub- cloud layer, even weak, high-based virga showers will be capable of triggering severe dry microbursts. While synoptic winds are only expected in the 10-15 mph range for much of the day, localized downburst potential could peak as high as 55 mph where these virga cores collapse. High-based showers and isolated thunderstorms will focus heavily over the higher terrain, though some wind gust potential exists into the Snake Plain as these outflow push away from any showers/storms that develop. There is a 30% to 70% chance of wind gusts exceeding 35 mph in proximity to any developing cell, with microburst potential again threatening gusts up to 55 mph. While a secondary wave of moisture will maintain a low-end chance for elevated overnight or early morning showers into Thursday, daytime heating will prompt another round of isolated to borderline scattered dry thunderstorms Thursday afternoon across the central mountains and eastern highlands.

A brief break in the pattern is anticipated early Friday morning before an unseasonably deep, early-summer low-pressure system begins to compress the regional pressure gradient. While afternoon showers and thunderstorms will redevelop over the high country with a slight increase in measurable rainfall, the non- convective gradient winds will be the primary story on Friday. Expect a substantial, widespread acceleration of synoptic winds across the area. Wind headlines may ultimately be required for portions of the Snake Plain, though lingering mid-to-high cloud decks could limit optimal boundary layer mixing and hold the strongest gusts just off the surface.

The core of this unseasonably strong upper-level low will swing directly across the Intermountain West over the weekend, delivering a dramatic transition to well below normal temperatures. Sunday will mark the thermal trough of the event, standing out as the coldest day of the week. Afternoon maximum temperatures will struggle to escape the 50s and lower 60s across low-elevation valleys, which represents a remarkable anomaly of roughly 20 degrees below normal for late June. Some record low max temperatures appear in jeopardy for the latter half of the weekend. In fact, the highest mountain peaks and ridges will likely see periods of accumulating snow. Furthermore, the region will pivot from limited moisture to a widespread soaking rain event, with storm-total liquid accumulations projected to exceed 0.50" some of the higher terrain. Valley locations will likely be limited to a few tenths at best but things are still in flux. Lingering showers will persist over northern zones on Monday before a high-pressure ridge ushers in a drying and moderating trend by next Tuesday as we head towards July.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 545 AM MDT Wed Jun 24 2026

VFR conditions expected through the period. There will be some mid/high level clouds in place across the region today along with the potential for some virga and dry showers/storms. Could see some gusty outflow winds associated with that activity later this afternoon around KBYI and KDIJ. For now, just maintained VCSH at these locations and kept synoptic winds of 10-15 kts for all eastern Idaho terminals and will continue to monitor trends to see if TEMPOs or PROB30s will be needed to account for any convective impacts. These would be in the form of gusty outflow winds as VSBYs or CIGs shouldn't be impacted.

FIRE WEATHER

Issued at 213 AM MDT Wed Jun 24 2026

As deep mid-level moisture moves over an exceptionally dry boundary layer, virga, dry lightning and gusty outflow winds will be common today and Thursday while the chance for any wetting rains will remain quite low. High country zones south of the Snake Plain (Zones 413 and 427) alongside parts of the central mountains (Zones 475 and 476) will navigate localized virga and isolated gusts today. Convective coverage expands to isolated and borderline scattered thresholds today and Thursday, keeping dry lightning risk elevated. While explicit Red Flag Warnings have not been issued for the mid-week period due to the isolated nature of the threat, trends will be watched closely. Friday introduces a widespread gusty wind event with non- convective gusts of 20 to 40 mph, though rapidly surging relative humidity levels should stave off widespread critical wind/RH thresholds. A complete seasonal reset occurs this weekend as a powerful low delivers cold temperatures, high humidity, mountain snow, and widespread wetting rains exceeding 0.25" for the mountains, though valley Zones 410 and 425 will remain dry with totals likely falling between 0.10" and 0.25".

PIH WATCHES/WARNINGS/ADVISORIES

None.