Area Forecast Discussion

KEY MESSAGES, Issued 1150 AM MDT Thu Jun 11 2026

- Cooler temperatures Thursday will again begin to warm through Friday and Saturday, reaching around 5-10F above seasonal normals, increasing further Monday through next week, reaching 10-15 degrees above normal with Moderate HeatRisk by Wednesday.

- Gusty winds may develop Friday afternoon across the Uinta Basin and Eastern Valleys alongside very dry relative humidities, leading to localized critical fire weather conditions.

- Increasing moisture over southern Utah will bring a few afternoon showers and thunderstorms over the higher terrain with the potential for isolated dry lightning Saturday and Sunday. Increasing winds Sunday into Monday will also increase the fire danger over southern Utah.

DISCUSSION, Issued 1150 AM MDT Thu Jun 11 2026

With a dry cold front largely through the region and dissipating with daytime mixing this morning, seeing temperatures 5-15F cooler than yesterday and expect this to reflect in the daytime highs in all but the warmest locations (Washington County) where temperatures will once again crest 100F+ this afternoon. Overall, this relief is expected to be short lived, with upper level temps gradually warming Friday and more significantly through the weekend into next week. As highs climb towards 93-95 degrees on the Wasatch Front and 105 in St. George by Tuesday/ Wednesday, risk of heat related illness will greatly increase. In fact, there is upwards of a 90% chance of HeatRisk reaching the "moderate" category (greatly affecting those sensitive to heat and those without access to adequate cooling/ hydration) and around a 15-20% chance of reaching the "Major" category (affecting a majority of the population).

A relative lull in upper level winds and increasing stability under building heights will also give some relief across the region from gusty winds that have been driving recent fire weather concerns. By Friday, an amplifying trough will begin to affect the overhead flow, putting much of the forecast area into a warm southwest flow regime, and driving surface temperatures back above climatological norms. While conditions will remain generally mild area-wide, the Uinta Basin and Eastern Valleys could see afternoon wind gusts pushing 20-35 mph in isolated areas with single digit relative humidities. While not expected to be widespread enough to drive impact headlines, this will be an area to keep an eye on.

In addition, this southwest flow will be able to tap into some available moisture in the mid and upper portion of the column and increase PWATs for the southern third of the state over the weekend. Ensemble means put total column water around 0.4-0.6 in, with a few outlier members from the EPS suggesting PWATs could reach as high as 1.1 in (upwards of 200-215 percent of normal). That said, both the current state of the lower atmosphere being so dry as well as the majority of the moisture in the source region being elevated would suggest high- based convection and more of a wind/dry lightning threat than a flooding threat late Saturday into early Sunday. If trends continue to move towards the more moist end of the spread, or the high resolution CAMs begin to suggest moistening of the lower atmosphere, this will warrant greater attention in the coming days. At this time, at least an isolated threat of flash flooding should be anticipated with the thunderstorm potential over slot canyons, dry washes, and recent burn scars.

AVIATION, Issued 114 PM MDT Thu Jun 11 2026

KSLC, Issued 114 PM MDT Thu Jun 11 2026... VFR conditions will prevail beneath blue skies at the KSLC terminal through the period. Diurnal wind shifts are expected to occur, with winds becoming southerly around 05z before becoming northwest once again around 16z tomorrow.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions will prevail across all of our sites through the TAF period beneath blue skies. KEVW is forecast to develop gusts in excess of 20kts tomorrow around 15-18z, diminishing by sunset.

FIRE WEATHER

Daytime highs today will run just a touch cooler in the wake of the dry cold front that has moved through, though the effect will be short-lived with temperatures quickly rebounding to above seasonal normals by Friday and remaining there through the weekend and into next week. With ridging/high pressure dominating overhead, a stable environment should keep skies clear and winds light for most zones. Southwestern Wyoming and northeastern Utah may observe increased wind gusts in the 20-30 mph range on Friday afternoon with a brief increase in upper level flow from a grazing trough far to the northeast. As a result, localized critical fire weather conditions may be observed in these areas with relative humidity values solidly in the low teens or upper single digits.

Models are in good agreement that there will be some degree of mid- and upper-level moisture incursion into southern Utah over the weekend. This has the potential to trigger isolated convective development Saturday and Sunday from the late afternoon through evenings, particularly across higher terrain. Wetting rain chances look extremely minimal, but what does develop will be capable of producing lightning and gusty erratic outflow winds. Moisture once again decreases into next week, with little to no chance of precipitation.

SLC WATCHES / WARNINGS / ADVISORIES

UT...None. WY...None.