230
FXUS65 KSLC 131007
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
407 AM MDT Wed Aug 13 2025

.SYNOPSIS...High temperatures peak on Wednesday with mostly dry
conditions. Moisture gradually increases through the remainder of
the week as temperatures come down closer to normal by the
weekend. Diurnal convection will primarily be high-based
Wednesday/Thursday before becoming wetter on Friday and Saturday.
Drier air moves into the area by Sunday.

&&

.SHORT TERM (Through 12Z/6AM Friday)...High pressure over the area
will lead to temperatures 5-8 degrees above normal and mostly dry
conditions. Temperatures will approach 100F for portions of the
Wasatch Front with lower Washington county as warm as 108F. An
Extreme Heat Warning has been issued for the Glen Canyon/Lake
Powell area as temperatures will be sufficient enough to result in
widespread major HeatRisk levels.

Mid-level moisture will begin to advect into the area today with
isolated high-based convection possible across the terrain. Given
the dry low-levels, any storms that do form will be capable of
producing gusty outflow winds. Moisture continues to increase on
Thursday with more scattered convection across much of the area.
Lower levels will still be relatively dry so outflow winds will
remain a concern along with dry lightning. Temperatures do come
down a few degrees by Thursday which will help to lessen the
HeatRisk.

.LONG TERM (After 12Z/6AM Friday)...
Limited moisture will remain in place Friday with a weak upstream
trough in place. Despite elevated PWAT values, surface dew points
are forecast to remain in the low 40s across much of southern and
central Utah, indicating the moisture more aloft than surface based.
This setup will continue to favor scattered showers and
thunderstorms, which will tend to be a mixture of wet and dry
storms. A very limited flash threat is likely to continue into
Friday, as outlined by the Marginal WPC Excessive Rainfall Outlook,
but it would likely take the wrong storm getting into the wrong
basin for the wrong amount of time, given this marginal
thermodynamic profile.

Saturday into beginning of next week, a drying trend is expected as
the region comes under the influence of large scale subsidence
associated with an amplifying ridge across the central and southern
Rockies. Thus any lingering convection will become more isolated and
terrain-tied through this drying period.

Ensembles seem to then be in excellent agreement about establishing
and amplifying a ridge near the Four Corners by the second half of
next week. Largely this will translate to seasonably slightly above
average temperatures continuing. While this could eventually open up
the door for monsoon moisture to sneak northward into Utah, through
the end of next week there is little indication from the global
ensembles that meaningfully deep moisture will be heading our way,
with generally a 20-30% percent chance of PWATs exceeding 0.9 inches
by next Thursday. Still expect to see a general increase in daily
scattered showers and thunderstorms especially over the higher
terrain by the second half of next week.

&&

.AVIATION...KSLC...VFR conditions will persist for the KSLC
terminal through the period. Dry conditions with a few high clouds
will continue. Light southerly winds transition to light northerly
winds in the afternoon.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist
for the entire airspace throughout the period. Mostly dry
conditions, with isolated terrain driven high-based convection
during the afternoon across the south, will continue. Expect light
diurnal winds with increasing southwesterly winds during the
afternoon across portions of the central and southern airspace.

&&

.FIRE WEATHER...High pressure over the area with an approaching
shortwave will keep relative humidity low with gusty west winds
across the Wasatch Mountains will create critical fire weather
conditions on Wednesday afternoon.

As this high pressure becomes oriented over the Four Corners
region mid-level moisture will advect into the area resulting in
more widespread diurnal high-based convection developing by
Thursday. Any storms that do develop will be capable of producing
gusty and erratic winds along with frequent lightning. Given many
areas have not seen appreciable precipitation in a significant
period of time and fuels are very dry, wildfire starts are
possible with any lightning strikes. A Fire Weather Watch has been
issued for these areas Thursday afternoon and early evening.

By Friday and Saturday more moisture should advect into the lower
levels to help limit critical fire weather conditions. Drier air
starts to advect into the region by Sunday.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Fire Weather Watch from Thursday afternoon through Thursday
     evening for UTZ478>481-483-484-488-489-493-494-496-498.

     Red Flag Warning from noon today to 9 PM MDT this evening for
     UTZ479.

     Extreme Heat Warning from noon today to 8 PM MDT this evening
     for UTZ131.

WY...Red Flag Warning from noon today to 8 PM MDT this evening for
     WYZ277.

&&

$$

SHORT TERM...Mahan
LONG TERM...Church
AVIATION...Mahan
FIRE WEATHER...Mahan

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