Garland, Utah Weather Forecast Discussion

651
FXUS65 KSLC 262111
AFDSLC
Area Forecast Discussion
National Weather Service Salt Lake City UT
311 PM MDT Fri Sep 26 2025
.SYNOPSIS...A slow moving upper level low will continue to bring
the threat of convection to southern Utah through the weekend,
expanding into eastern utah Sunday. A cold front is expected to
cross northern Utah Tuesday, with gusty southwesterly winds across
southern Utah ahead of the front.
&&
.SHORT TERM (Through 12Z/6AM Sunday)...A broad closed low is
centered just south of the Arizona/Nevada/Utah triple point this
afternoon, moving very slowly eastward. This is bringing a tongue
of increased moisture into southern Utah, with widespread values
around 0.7 inch and up to around 0.9 inch in the southwest corner
of the state, per polar satellite imagery. The position of the low
and associated jet is providing good instability, with CAPE values
approaching 1000 J/kg in the far southwest corner. Shear is much
less favorable today, but still seeing a bit of organization to
the developing convection. Any storms that develop, given the
moist airmass, will be capable of producing heavy rain that could
lead to flash flooding as well as strong, gusty winds and small
hail. Existing convection will weaken significantly for the mid
to late evening.
The low is expected to creep rather slowly to the east through
Saturday, so little change in the overall pattern is expected
through the afternoon. As a result, will see another day of
showers and thunderstorms primarily focused over southern Utah,
though cannot rule out a few showers over the higher terrain over
central and southern Utah. Northern Utah maxes will be near to
just above seasonal normals, while the increased cloud cover and
coverage of showers and thunderstorms will keep temperatures
cooler over southern Utah, particularly over southwest portions of
the state.
.LONG TERM (Through 12Z/6AM Sunday)...The cutoff low over the desert
southwest will begin to phase back into the mean flow on Sunday
bringing scattered convection to the area on Sunday. A deep trough
over the PNW will likely stay centered off the PNW coast, but it
will bring through a couple of shortwaves throughout the week that
will increase precipitation chances in addition to a cooler airmass.
Sunday is expected to be the warmest day of the period across
northern Utah and SW Wyoming with highs a few degrees above normal.
Temperatures will be a few degrees below normal on across southern
Utah as cloudy conditions limit the usual diurnal warming. Moisture
will be in place for most of the area with PWATs between 0.6"-0.9".
The limiting factors in strong and more widespread convection will
be from the low(ish) cape/low shear environment and the weaker
dynamics with this low phasing back into the mean flow. Therefore,
anticipating more convection tied to the terrain, although any storm
that gets into a flood prone area will be capable of producing some
flash flooding.
Heading into early next week we will see shortwaves moving through
the area as a deeper trough off the PNW coast remains fairly
stationary. The first shortwave moves into the Great Basin on Monday
with a frontal passage across northern Utah most likely on Tuesday
bringing the potential some widespread stratiform precipitation to
northern Utah. This precipitation is conditional on the southern
extent of the shortwave. Right now 54% of ensemble members keep the
shortwave further north and west which would keep most of the
precipitation to the north. The other 46% of guidance have it coming
far enough south to bring precipitation to at least northern Utah
and SW Wyoming. Regardless, a weak cold front should move through
bringing temperatures ~5 degrees below normal.
Wednesday and Thursday appear to be mostly dry as drier air advects
in behind the front. However, another shortwave by the end of next
week is represented in 46% of the guidance (the other 54% keep this
to the north with dry conditions) that would bring more
precipitation chances to northern Utah/SW Wyoming.
&&
.AVIATION...KSLC...Light northwest winds will transition to
southeast around 04Z. Mostly clear conditions will last through the
morning, with a transition to northwest winds around 18Z. Scattered
to broken clouds in VFR range will build in after 18Z.
.REST OF UTAH AND SOUTHWEST WYOMING...Showers and thunderstorms
capable of locally heavy rain and gusty, erratic outflow winds for
southern Utah will taper off from 00-03Z. Mostly cloudy conditions
will continue through the TAF period for that portion of the state,
with more showers and thunderstorms after 18Z. Elsewhere, mostly
clear conditions will last through 18Z. Clouds will increase from
southern Utah into southwest Wyoming and northern Utah through the
day.
&&
.FIRE WEATHER...Low pressure near the California/Arizona border will
continue slowly eastward across the Desert Southwest over the
weekend as it weakens. Through Saturday, the best instability will
be focused over southern Utah, where any storms that develop could
produce gusty winds and heavy rain capable of flash flooding. By
Sunday the threat will spread into eastern Utah. After a brief
lull on Monday, a cold front moving across northern Utah during
the day Tuesday will bring cooler temperatures and a threat of
precipitation. Ahead of the front, winds will become breezy out of
the south as conditions remain generally dry. Somewhat unsettled
conditions are expected to continue thereafter.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&
$$
SHORT TERM/FIRE WEATHER...Traphagan
LONG TERM...Mahan
AVIATION...Wilson
For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity

NWS SLC Office Area Forecast Discussion