textproduct: Salt Lake City

KEY MESSAGES, Issued 1034 PM MDT Thu Sep 24 2026

- Isolated to widely scattered convection across southern and central Utah Friday.

- An approaching trough will bring cooler temperatures and 50% chance for widespread precipitation Sunday-Tuesday, with tropical moisture potentially leading to locally significant amounts.

DISCUSSION, Issued 1034 PM MDT Thu Sep 24 2026

Weak, diffuse low pressure is in place this evening across AZ and extending into UT and eastern CO. This, combined with PWATs near 0.7 inches allowed isolated to widely scattered weak convection to develop over mainly the southern Utah mountains this afternoon which have now mostly dissipated, leaving some mid and high clouds in place that will continue over much of southern and eastern Utah into Friday morning.

An upper trough currently noted off the PacNW coast will make its way inland tonight, crossing ID Friday before ejecting across western MT. Ahead of this trough, isolated to widely scattered convection can be expected once again Friday afternoon. These are expected to develop over the southern and central Utah mountains, then shift into the adjacent eastern valleys with the flow aloft turning more westerly. A shallow cold front will push into northwest Utah Friday night, bringing slightly cooler temperatures to that area through Saturday.

With generally dry and stable conditions expected on Saturday, attention then turns to the next trough, which will be deepening off the West Coast on Sunday. Ahead of this trough, a vort max originating near Hurricane Odalys in the eastern Pacific is progged to lift into Utah Sunday afternoon, bringing an increase in moisture and some widely scattered convection. The trough itself is progged to approach Utah by Monday. Latest deterministic EC/GFS and an increasing number of global ensemble members are trending towards a splitting, closed-low evolution, which would bring the system farther south with a slower eastward progression. This would result in the system being able to better tap moisture from Hurricanes Odalys and Polo, with longer duration precipitation potentially aiding greater amounts. Widespread precipitation appears likely across southern and eastern Utah, but at this time, quite a bit of uncertainty remains with regards to precipitation amounts, with a large spread in the NBM 25th-75th percentile amounts. For example, many southeast Utah valley areas have 48-hr totals Monday through Tuesday of 0.10 inches or less at the 25th percentile but around 1 inch or more at the 75th percentile. However, even with the uncertainty, the amounts at the higher end of the probabilistic spectrum have been climbing, meaning increasingly greater amounts are becoming possible.

Besides precipitation, the trough will bring cooler temperatures into the area, with afternoon maxes falling 5-10 degrees below normal for Monday and Tuesday, with many valleys reaching low 70s at best. Temperatures will slowly rebound midweek as the storm system exits the area, but significant spread exists in the large scale pattern for the second half of next week.

AVIATION

KSLC...The SLC terminal will see VFR conditions throughout the day with increasing high clouds. Southerly winds are expected to shift to the northwest between 20Z and 22Z, with a 30 percent chance this shift will occur later than expected or not at all.

REST OF UTAH AND SOUTHWEST WYOMING...The airspace will see VFR conditions throughout the day with increasing high clouds for eastern portions of the area. Isolated showers and thunderstorms will again develop over the higher terrain of southern Utah this afternoon, bringing a low chance of gusty and erratic winds. Elsewhere, dry conditions will prevail with increasing winds out of the south.

FIRE WEATHER, Issued 444 AM MDT Fri Sep 25 2026

Conditions will stay generally dry and seasonable across Utah through much of the weekend, though the higher terrain of southern Utah will see some isolated showers this afternoon into the early evening. Southerly winds will pick up over the weekend ahead of a Pacific trough expected to move through the area Monday into Tuesday. The passage of the storm system will bring the potential for more widespread precipitation, particularly if it interacts with tropical moisture. Drier conditions are then expected to return for much of the remainder of the upcoming week.

SLC WATCHES/WARNINGS/ADVISORIES

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