518
FXUS65 KSLC 110828
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
228 AM MDT Fri Sep 11 2026

.KEY MESSAGES, Issued 1032 PM MDT Thu Sep 10 2026...


- A marginal risk (level 1/4) for excessive rainfall is in place
  across portions of southern Utah Friday through Sunday.

- There is a ~50% chance the northern valleys will see wind gusts
  in excess of 45 mph for 3 or more hours Saturday evening into
  late Saturday night ahead of a strong cold front.

&&

.DISCUSSION, Issued 1032 PM MDT Thu Sep 10 2026...
A weak shortwave crossing the region embedded in
quasi-zonal flow continues to shift across northern Nevada into
northern Utah through the overnight hours. Mainly high-based
showers are noted on radar moving into far western Utah. A few
locations may see a period of light rain overnight, but widespread
rain is not expected. Given decoupling, don`t expect much of a
gusty, microburst wind threat with this high-based convection.

As broad troughing engulfs the Pacific Northwest, the upper level
ridge will continue to flatten, allowing for modest moisture
advection to shift into southern Utah Friday. The bulk of the CAMS
indicate that the highest threat of isolated to widely scattered
thunderstorms will be across southern and eastern Utah Friday
afternoon into Friday evening. Given the net moisture increase,
WPC has outlooked this area in a marginal risk for excessive
rainfall. This correlates well with conceptual models and
guidance. The flash flood potential product for the southern Utah
national park and rec areas has every location in a "possible" for
Friday.

By Saturday, weak subsidence will likely suppress convection in
most locations, though isolated thunderstorms across far eastern
portions of the CWA including the Swell and Capitol Reef area will
represent a low end flash flood threat.

As early as Saturday evening, another period of moisture advection
will shift into southern Utah ahead of a strong cold front. This
front continues to slow down in each iteration of guidance...now
looking to reach northwestern Utah after sunrise Sunday, reaching
southern Utah by Monday morning. This may provide another window
with enhanced moisture for another round of at least isolated to
widely scattered thunderstorms across southern and eastern Utah
ahead of the cold front.

As far as gusty winds ahead of the cold front, it will be a battle
between decoupling and a strong gradient whether northern valleys
will see advisory level winds Saturday evening/night into early
Monday. NBM probs still suggest around a 50% chance wind advisory
criteria will be met, but the later this cold front shifts, the
less likely wind advisory criteria will be met.

Much cooler temperatures will build into the region by Monday.
Given the slower cold front timing, the cooldown Sunday isn`t as
aggressive, around 10-15 degrees across northern Utah, with around
another 5 degrees of cooling by Monday.

Longer range, southern and eastern Utah is outlooked in a
moderate risk for heavy precipitation between the 18th and 20th.
Something to keep an eye on...and an indication that an extended
period of dry conditions is the less likely outcome through the
next few weeks.


&&

.AVIATION, Issued 1032 PM MDT Thu Sep 10 2026...


KSLC...VFR conditions are expected at the SLC terminal through the
overnight hours. A weak storm system will bring a low (20-30
percent) chance of gusty and erratic winds from showers, most likely
between 08Z and 14Z. Otherwise, southerly winds are expected to
shift to the northwest between 18Z and 20Z.

REST OF UTAH AND SOUTHWEST WYOMING...The airspace will see VFR
conditions through the night with generally light and terrain driven
winds. A weak storm system will bring a low (20-30 percent) chance
of gusty and erratic winds from showers for northern portions of the
airspace from the early morning to near sunrise. By mid-morning, the
most likely area for showers will shift to southwestern portions of
the airspace, with the low chance of gusty and erratic winds from
showers persisting through about midday.

&&

.FIRE WEATHER...A weak grazing system will continue to push a
correspondingly weak boundary into northern Utah into Friday
morning, bringing increased moisture, cloud cover, and isolated
shower chances. Isolated convective redevelopment is then expected
across portions of southern Utah Friday afternoon.

Moving into the weekend, the next approaching system will bring
increasing deep southwesterly flow. Winds will tend to increase,
especially in unsheltered valley locations across western Utah,
with daytime gusts around 25-40 mph. Models continue to fluctuate
on timing of a cold frontal boundary with this system. In general,
and especially if during the day, southwest winds will increase
and become maximized ahead of this frontal passage, with a briefer
period of gusty northwest winds likely following the front.
Largely, this front is expected to by dry in nature with the best
chance of precipitation noted across portions of eastern Utah
where moisture is favored to be higher. An unsettled pattern will
yield continued isolated to at times scattered convective chances
along and east of Utah`s high terrain through midweek. There is
considerable uncertainty in if, and to what extent, tropical
moisture may then combine with another system later in work week.

&&

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

$$

PUBLIC...
AVIATION...
FIRE WEATHER...Warthen

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