791
FXUS65 KSLC 022127
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
327 PM MDT Tue Sep 2 2025

.SYNOPSIS...Warm and dry conditions will remain in place across
Utah and southwest Wyoming through the evening. Moisture
gradually increases Wednesday onward, bringing increasing chances
for showers and thunderstorms, especially by the weekend. Drier
conditions are expected to develop early next week.

&&

.SHORT TERM (Through 12Z/6AM Thursday)...High pressure remains
centered over Utah and southwest Wyoming this afternoon. Though
scattered showers and storms have developed over Nevada and
Arizona this afternoon, seeing only higher terrain cumulus over
the area as conditions remain dry. Highs are currently running up
to 5F above seasonal normals with light winds.

The pattern over the area will start to change beginning tomorrow.
Though high pressure will remain over the region, the flow aloft,
particularly for southern Utah, will becoming more southerly,
which will allow monsoon moisture to ease back into the area. It
looks like most of the moisture increase will be confined to
southern Utah, southwest Utah in particular, for Wednesday, with
scattered storms expected to develop there as most of the
remainder of the state remains dry. Moisture will be initially
high based, so gusty microburst winds will be the primary threat
with storms that develop. These storms are expected to produce
little in the way of rainfall, limiting the flash flood threat.

.LONG TERM (After 12Z/6AM Thursday), Issued 336 AM MDT... As the
axis of an upper level ridge begins to shift eastward through the
latter half of the week an influx of moisture is expected to
spread across Utah and southwest Wyoming.

Key messages:

 - Increasing moisture from Thursday through Friday/ Saturday
   will bring increasing chances for showers and thunderstorms
   across the area.

 - Storms developing late in the week will likely be slow moving,
   bringing higher likelihoods of producing heavy rainfall and
   flash flooding in slot canyons, slickrock areas, normally dry
   washes, and recent burn scars.

 - Seasonal temperatures will drop back to below normal levels as
   afternoon convection, increased cloud cover, and overall
   cooler overhead temperatures spread over the region late in the
   week/ over the weekend.

By Thursday, surface high pressure will continue to weaken across
Utah and southwest Wyoming as the center of the ridge drifts
eastward. Coincident with the movement of the ridge, overhead
temperature anomalies will also shift eastward which will initiate a
gradual cooling trend through the remainder of the week. Lower level
moisture will continue to be suppressed to southern/ southwest Utah
on Thursday afternoon as a deeper, moist southerly flow will be
lacking, however, layer PWAT values will still be running 150-175%
of normal across southern Utah. That said, any storms developing
during the afternoon hours across southern Utah will have a
relatively slow storm motion (10kts or less), increasing the overall
risk of heavy rainfall and flash flooding.

A more established southerly flow is expected to develop overnight
into Friday, helping to advect greater moisture into Utah and
southwest Wyoming. Storm motions on Friday will remain relatively
slow and we`ll begin to see an expanding threat of heavy rainfall/
flash flooding into central Utah. Moisture is currently expected to
peak during the overnight hours into Saturday morning. This peak
moisture is anticipated to pair with a shortwave trough being
ejected from an upstream longwave trough off the U.S. West Coast. At
the very least, chances for showers and thunderstorms will be
maintained through the overnight hours into Saturday, with Saturday
seeing the best chances for scattered to widespread showers and
thunderstorms.

Conditions gradually dry out from Sunday forward as dry
southwesterly flow persists across the region.

&&

.AVIATION...KSLC...VFR conditions will prevail for the KSLC terminal
through the period. Dry conditions with clear skies will continue
with light and diurnally driven winds.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will prevail
for the entire airspace through the period. Dry conditions with a
few mid level clouds will continue with light and diurnally driven
winds.

&&

.FIRE WEATHER...High pressure will remain over the area over the
next few days, but will shift enough to allow moisture to slowly
move into the area Wednesday into Thursday. This will result in
an increase in coverage of convection for southern Utah, with any
storms developing being high based, with gusty winds as the main
threat. A more substantial increase in moisture is expected Friday
into the weekend, resulting in more widespread coverage of
showers and thunderstorms and an increasing chance of wetting
rainfall. Temperatures will gradually decrease as the moisture
increases, running below normal by the weekend. Drier weather is
expected to return early next week.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

SHORT TERM/FIRE WEATHER...Traphagan
LONG TERM...Webber
AVIATION...Mahan

For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity