460
FXUS65 KSLC 050438
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
1038 PM MDT Fri Sep 4 2026

.KEY MESSAGES...


- Gusty winds out of the southwest persist through at least Sunday
across much of Utah and southwest Wyoming, with an emphasis on areas
west of I-15.

- Tropical moisture advects north into Utah Sunday increasing
  chances for precipitation, but uncertainty remains regarding QPF
  totals.

- There is a slight risk for flash flooding along with the
  potential for some strong thunderstorms.

- There is ~45% chance that tropical moisture returns towards the
  end of next week.


&&

.DISCUSSION...An impressive early season trough is currently
positioned across the Pacific Northwest and is producing a notable
thermal gradient with high temperatures across Utah in the upper
80s to low 90s while areas to our northwest in southwestern Idaho
struggled to get out of the 50s. This thermal gradient is also
coinciding with a pressure gradient that has kept winds gusty out
of the southwest across much of the area with max wind gusts
between 30-40 mph with a few isolated locations between 45-55 mph
(briefly). This trough will continue to linger over the next
couple of days just to our northwest which will keep winds
elevated and similar in magnitude to what we have experienced the
past couple of days.

The base of this trough will rotate through the Great Basin on
Sunday while pulling in tropical moisture from Hurricane Marie.
This moisture is slated to arrive Sunday morning in tandem with
a 110+ kt jet. The majority of the guidance has Utah positioned in
the right entrance region of this jet leading to upper-level
diffluence and a narrow swatch of relatively heavy precipitation.
There are some differences in the solution, however with much
drier solutions. The 10th-90th percentile QPF totals range from
almost nothing to upwards of 1.00"+ of precipitation from a band
that sets up from southwest Utah up through southwestern Wyoming.
Additionally, the arrival of a cold front late Sunday into Monday
morning will provide another area of focused convection with the
majority of guidance pinpointing northwestern Utah as the favored
location of this convection. A high shear/low cape environment is
denoted amongst most guidance which could lead to some quasi-
linear convection with the potential for strong gusty winds.

The post-frontal airmass will bring cooler and drier weather into
the region through the first half of the week. Beyond that,
ensemble members become divergent with a 45/55 split of a wet/dry
pattern. The 45% of members phase the remaining moisture of
Hurricane Marie into a trough across the PNW with a trajectory
into the Great Basin. The other 55% of members phase this moisture
into a low off the PNW coast which would lead to a drier solution
for the Great Basin.

&&

.AVIATION...

KSLC...Ongoing pattern expected to persist with dry southwesterly
flow. At times when winds relax overnight, modest low level shear
around 30-35 kts is anticipated through 2 km AGL or so. Gusts will
redevelop following sunrise and persist through the day, once again
relaxing by later in the evening. VFR conditions prevail with some
high clouds beginning to filter in Saturday night.

REST OF UTAH AND SOUTHWEST WYOMING...A pattern dominated by dry
southwesterly flow will persist. At area terminals where winds relax
overnight, modest low level shear of around 30-35 kts through the
first 2 km AGL or so is anticipated. Occasional high clouds will
filter in, especially beginning Saturday night, but VFR conditions
prevail.

&&

.FIRE WEATHER, Issued 123 PM MDT Fri Sep 4 2026...
Moisture will continue to gradually increase into
the weekend as southwesterly flow pushes moisture further north.
Today and tomorrow, expect locally critical fire weather
conditions primarily across the West Desert and Great Salt Lake
Desert where humidities may drop below 15%. Additionally, strong
wind gusts across areas primarily west of I-15 will range from
30-45mph each afternoon into Sunday.

On Sunday, a stronger push of moisture arrives to Utah with
widespread showers and thunderstorms across the state, though
primarily across central and southern Utah. Temporary drying is
expected Monday and Tuesday, though the pattern developing midweek
supports another round of moisture pushing north subsequently
increasing chances for showers and thunderstorms across Utah once
again.

&&

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

$$

PUBLIC...Mahan
AVIATION...Warthen
FIRE WEATHER...Worster

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