textproduct: Salt Lake City

KEY MESSAGES, Issued 1005 PM MDT Thu Jun 18 2026

- Dry conditions will continue Friday, with northern Utah seeing the hottest temperatures of the season so far. This will bring an increased risk of heat related illnesses along portions of the Wasatch Front. The risk will decrease over the weekend as a weak and mostly dry cold front brings temperatures within 5F of seasonal normals.

- Another round of gusty winds up to 30-40 mph combined with very dry relative humidity values will bring the threat of critical fire weather conditions to western Utah on Friday, with the threat potentially moving into southern and eastern Utah Saturday. - High pressure will rebuild for early next week, keeping conditions dry with a steady warming trend in temperatures. The potential for heat related illness could increase for some valleys by the middle of next week.

DISCUSSION, Issued 1005 PM MDT Thu Jun 18 2026

An elongated ridge axis stretches roughly northwest to southeast across Utah and southwest Wyoming this evening. Very dry conditions persist across much of the area, but the westerly flow over southern Utah has allowed a small amount of moisture to move in, enough to produce a few showers and thunderstorms over the higher terrain this afternoon. Highs averaged about 5F above seasonal normals for northern portions of the forecast area, and approaching 10F above climo over southern Utah.

The ridge will continue to shift east, into Colorado by the afternoon, as a disorganized trough approaches the Pacific coast. This will bring increasing southwest flow to the area, breeziest over west central and southwest Utah where it will combine with the dry conditions to produce areas of critical fire weather conditions. The position of the trough will also allow drier and less warm air to advect into southern Utah as northern portions of the area see the hottest temperatures of the year so far. Highs are forecast in the mid to upper 90s along the Wasatch Front with overnight lows only dropping into the upper 60s to around 70, providing little relief from the heat. Because of this, HeatRisk values will be in the red (major) category for lower portions of the Salt Lake Valley and northern Wasatch Front. Because of the increased risk of heat related illnesses for the general population, a Heat Advisory will be in effect tomorrow afternoon and evening.

The center of the trough is still expected to graze northern Utah late Friday into Saturday morning, though guidance continues to trend slightly farther north with the center of the trough. However, the potential for precipitation over northwest Utah during the day Saturday has gone up just a bit with this package, as the track of the trough would put the jet in a more favorable position for convection. Given the very dry lower levels, any storms that develop will produce little if any rainfall and will have the potential to produce gusty and erratic winds. The system will have a greater impact on temperatures, with highs returning to values within 5F of seasonal normals both Saturday and Sunday, though given the more northerly track of the trough, high temperatures have gone up ever so slightly for the weekend. Persistent gusty winds from the trough could combine with the dry conditions to produce areas of critical fire weather conditions across portions of southern and eastern Utah.

By Monday, the trough will have exited the area and there is high confidence that behind it the Pacific ridge will rebuild over the Great Basin. This will bring a steady warming and drying trend to start the week, with the ensemble mean showing high temperatures rising to up to 15F above seasonal normals again by the middle of next week, which could bring the potential of heat related concerns back into the forecast.

AVIATION, Issued 1005 PM MDT Thu Jun 18 2026

KSLC, Issued 1005 PM MDT Thu Jun 18 2026... Light southerly winds shift northwest between around 18Z to 20Z Friday. Some increase in cloud cover above ~15 kft will occur Friday, but VFR conditions expected to prevail. There is around a 20-30% chance for high based virga showers to bring gusty outflow winds on the order of 30-35 kts with timing favored between 02-04Z Saturday. Excepting this, southerly winds should return for the overnight.

REST OF UTAH AND SOUTHWEST WYOMING...Varying degrees of mid to high level VFR cloud cover will persist across much of the region through the TAF period. At northern terminals, there is ~20-30% chance of high based virga showers bringing gusty outflow winds ~30-35 kts between roughly 01Z to 06Z Saturday. Otherwise, most terminals will see diurnally normal winds through the TAF period, with some modest afternoon gusts up to around 25 kts at more exposed and typically breezy terminals.

FIRE WEATHER

Currently, high pressure remains to our south with a low pressure system to our west influencing the hot, dry, and windy conditions that will persist into the weekend. This will also result in very low humidities through the period with notably poor recoveries across central and southern UT into the weekend. The system to our west will gradually slide east with time, potentially sparking some dry thunderstorms capable of strong gusts and lightning tomorrow afternoon across much of UT.

Tomorrow, the system to our west looks to continue pushing further inland keeping winds elevated across UT. Confidence has increased regarding the development of more organized dry thunderstorms across northern UT in the afternoon hours, primarily across northern UT. Strong to severe gusts are expected with any storm that forms with more frequent lightning compared to Friday.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Heat Advisory from noon today to 6 AM MDT Saturday for UTZ104- 105.

Red Flag Warning from 3 PM this afternoon to 3 AM MDT Saturday for UTZ492-495.

Fire Weather Watch from Saturday afternoon through Saturday evening for UTZ482-484-488-489-493-494-496-498.

Red Flag Warning from 3 PM this afternoon to midnight MDT tonight for UTZ497.

WY...None.