524
FXUS65 KSLC 042324
AFDSLC

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

.KEY MESSAGES, Issued 123 PM MDT Fri Sep 4 2026...


- 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.

- Threats for both flash flooding and severe weather look to develop
on Sunday with the arrival of tropical moisture.

- The active upper air pattern continues into next week, potentially
resulting in more precipitation by mid-week following an early week
lull.


&&

.DISCUSSION, Issued 123 PM MDT Fri Sep 4 2026...
Currently, a large upper low is slowly moving into the
Pacific NW, deepening with eastern extent. A tight southwest-
northeast oriented pressure gradient exists across nearly all height
levels resulting in another afternoon of enhanced southwesterly flow
overhead. With another clear and dry afternoon, mixing has already
begun as surface temperatures warm up statewide with enhanced
southwesterly gusts making it down to the surface. Most areas across
UT and SW WY can expect to see gusts in the 25-35mph range, though
areas west of I-15 may see gusts approach (and potentially exceed)
45mph given stronger winds aloft with higher surface temperatures to
encourage stronger mixing. This general pattern is expected to
continue into Sunday with enhanced afternoon dry southwesterlies
developing around the 10AM-12PM timeframe each day.

Come Sunday, moisture associated with Hurricane Marie is forecast to
phase into the mean upper flow as a result of the southern stream
increasing in strength. As a result, PWAT anomalies on the order of
0.5-0.8 above seasonal normals (potentially exceeding 200% normal
values) are forecast to push north across much of Utah. Widespread
ascent will overspread as the strengthening southern stream phases
into the mean flow with the aforementioned upper low, resulting in a
somewhat quicker eastward progression over time. As such, widespread
showers and thunderstorms are forecast to develop in the morning
hours across much of southern and central UT, potentially nudging
into northern UT as well. While enhanced flow aloft suggest fast
moving storms, the overall moisture content within the atmosphere
and preceding wet conditions from rainfall earlier this week across
portions of central and southern UT leads to some degree of flash
flooding concerns on Sunday. Current guidance suggests hourly
rainfall rates ranging from 0.4-0.6"/hr, with some isolated rates
nearing 0.8-1"/hr rates possible. Some uncertainties still exist
with this setup, particularly surrounding how quickly the system
ultimately moves out of the region, though heavy rainfall appears
likely regardless of timing.

Additionally, a mentionable threat for severe weather exists across
primarily northern and central UT Sunday afternoon given the
strength of the upper trough. Bulk shear values ranging from 30-
50kts appears likely given the strength and persistent deepening of
the upper level low, though timing may serve to limit this event
overall. Previous runs were much slower with the progression of this
system, though guidance has sped up the eastward progression
considerably over the last day. This has resulted in a shorter
window for destabilization, with limited CAPE areawide keeping this
event more isolated than previously thought with respect to severe
thunderstorms. Regardless, an impressive kinematic environment
exists and trends will be monitored going forward.

Come Monday and Tuesday, the upper low progresses east leaving the
forecast area in a dry westerly flow regime keeping conditions calm
to start the week. Come Wednesday, another shot of moisture looks to
advect north as another strong upper low dives south along the CA
coastline putting the forecast area beneath enhanced southwesterly
flow once again. Considerable uncertainty remains in place regarding
the upper air pattern moving into later next week and the
progression of the aforementioned upper low, though a return to a
wetter pattern appears favored following Wednesday next week.


&&

.AVIATION...

KSLC...VFR conditions will persist for the KSLC terminal through the
period. Dry conditions will continue with a few high clouds. Winds
will remain breezy out of the south for the duration of the period
with the strongest wind gusts during the day.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for
the entire airspace through the period. Dry conditions will continue
with a few high clouds. Winds will remain breezy out of the
southwest for the duration of the period with the strongest wind
gusts during the day.

&&

.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...Worster
AVIATION...Mahan
FIRE WEATHER...Worster

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