Flash Flooding and Damaging Winds in Utah, July 14 to 18, 2025

Area Forecast Discussion
National Weather Service Salt Lake City UT
349 PM MDT Mon Jul 14 2025

.SYNOPSIS...Hot conditions will prevail alongside high-based
showers and thunderstorms through at least Wednesday, with
fairly widespread critical fire weather conditions on Tuesday.
Moisture increases in the lower levels by Thursday across far
southern Utah, bringing increasing risk of heavy rainfall through
at least Saturday. Conditions dry out once again late in the
weekend/ early next week.

&&

.SHORT TERM (Through 12Z/6AM Wednesday)...Big picture key messages
for Tuesday's forecast are as follows:

	- Widespread critical fire weather conditions expected across
   mainly the western half of Utah. For southern Utah, the
   concerns relate to strong southwest winds and low relative
   humidity. For northern Utah, the concern will be for scattered
   dry thunderstorms following an extended dry period.

	- High-based showers and thunderstorms will bring an increased
   risk (Marginal Risk) of strong outflow winds across northern
   Utah, with potential wind gusts in excess of 45-50 mph through
   the afternoon hours.

	- Hot temperatures will remain in place across Utah and southwest
   Wyoming on Tuesday, reaching their peak values for the week in
   the northern area.

Today, we've already seen modest increases in mid-level moisture
across much of Utah which has lead to isolated high-based showers
and thunderstorms across western Utah/ eastern NV and southern
Utah. Today, these high-based showers are not expected to bring
many issues, however, isolated strong wind gusts due to outflows
may arise in the aforementioned areas. This shower activity is
expected to decrease right around sunset this evening, with skies
clearing overnight. Hot temperatures across southern Utah will
wane as we head into tomorrow, with today marking the peak in
temperatures in this area. Existing Extreme Heat Warnings remain
in effect through 9PM this evening.

Heading through tomorrow, a shortwave trough moving across
southern Idaho will bring an increase in southwesterly winds
across the southern half of Utah. These winds, combined with
relative humidity around 15 percent or less (particularly below
8000ft) will create critical fire weather conditions on Tuesday
afternoon across the southern half of Utah (excluding the lower
elevation eastern valleys). In addition to the dry low level
environment, mid-level moisture increases are expected as this
trough pushes in greater moisture from the west, bringing an
overall increase in high-based shower and thunderstorm coverage.
Scattered dry thunderstorms (producing less than 0.1 inches of
rain) are expected across northern Utah during the mid-to-late
afternoon hours across northern Utah, warranting a Red Flag
Warning for scattered dry thunderstorms following an extended dry
period. These scattered high-based showers and thunderstorms will
bring increased potential to generate strong outflow wind gusts in
excess of 45-50 mph across this same area, raising the overall
critical fire weather risk, as well as a general severe weather
risk. A "Marginal" risk for severe weather has been issued by the
NWS Storm Prediction Center (level 1 of 5 risk).

Aside from the widespread critical fire weather conditions, the
hottest temperatures of the week are expected across northern/
central Utah and southwest Wyoming as temperatures increase
overhead. Along the Wasatch Front, Cache Valley, and central Utah
are expected to be in the upper-90s to low-100s. For the Uinta
Basin and Uinta County, WY, temperatures will rise into the
upper-80s to mid-90s. A weak frontal boundary will move across the
northern area overnight into Wednesday morning, bringing at least
some "cooler" temperatures to the urbanized areas... or at least
cool enough to reduce the overall Heat Risk.

.LONG TERM (After 12Z/6AM Wednesday), Issued 404 AM MDT...
Ridging aloft remains over
the area, although we should see some "relief" from the hot
temperatures of Tuesday, if you can really call it that. Following
the passage of an upper trough to our north, "cooler" air will
filter into the region bringing temperatures to just below or normal
for this time of year. Temperatures for the majority of our valleys
will generally range from the lower 90s to mid 90s while lower
Washington county will see temperatures in the low 100s.

Modest moisture return is expected to persist through the long term
period as an upper low develops and meanders over the Baja Peninsula
and southern CA. This will result in PWATs generally ranging from
around 0.5-0.7" across the majority of UT and southwest WY for the
majority of the long term forecast. Additionally, both the GFS and
EURO are hinting at a chance for PWATs ranging from 1-1.2" across
southern UT Thursday-Saturday. While this remains far out in time,
it does raise some concern for locally heavy rainfall which could
result in flash flooding. Specifics are somewhat difficult to iron
out at this time, though it bears watching.

&&

.AVIATION...KSLC...VFR conditions will persist at the KSLC terminal
through the TAF period. Gusty northerly winds may persist until 04-
05z before shifting to the southeast if current showers in NW Utah
persist after sunset...thus added a Prob30 for periods of gusty and
erratic winds should these showers impact the terminal.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected to
persist through the TAF period. Generally diurnal winds continue
while the overall flow remains light across UT aside from typical
gusty westerlies at KEVW. The slight chance for isolated showers and
thunderstorms near KCDC and KBCE continues into early evening, with
a potential for gusty and erratic winds.

&&

.FIRE WEATHER...A shortwave trough moving through southern Idaho on Tuesday afternoon
will bring increasing winds out of the west to southwest across
southern Utah and increasing mid-level moisture across much of the
area. With poor humidity recoveries still in place across much of
the area leading into Tuesday morning, an extended period of dry
conditions alongside the expected breezy afternoon winds,
potential for high-based dry thunderstorms, and the current fuels
and fire behavior advisory, critical fire weather conditions are
expected across a majority of the western half of Utah on Tuesday.
Elevated fire weather conditions are still expected across the
eastern half of Utah on Tuesday as breezy winds combine with dry
afternoon conditions, in addition to isolated dry thunderstorm
potential following an extended dry period. Various Red Flag
Warnings have been issued for gusty winds and low relative
humidity across the southern half of Utah (excluding the eastern
zones) and for scattered dry thunderstorms across northern Utah
(mainly from the Wasatch Mountains westward to the Nevada border).

Moisture will continue to increase in the mid-levels of the
atmosphere from Wednesday forward, bringing an overall increase in
humidity (during both the afternoon and overnight hours). Daily
chances for isolated to scattered thunderstorms is expected over
the higher terrain, especially across the southern half of Utah.
These storms, at least through Wednesday, will produce little, if
any, rainfall at the surface and will bring greater potential for
dry lightning strikes and gusty outflow winds. By Thursday, lower
level moisture begins to creep into southern Utah, bringing higher
chances for wetting rains as well as solid improvements to
relative humidity values across the region. This moisture is
expected to linger across mainly the southern half of Utah through
at least Saturday before decreasing late in the weekend/ early
next week as drier air moves into Utah from the west.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Red Flag Warning from noon to 9 PM MDT Tuesday for UTZ478-479.

     Red Flag Warning from noon to 11 PM MDT Tuesday for UTZ492-493-
     495>498.

     Extreme Heat Warning until 10 PM MDT this evening for UTZ123-124.

WY...None.
&&

SHORT TERM...Webber
LONG TERM...Worster
AVIATION...Verzella
FIRE WEATHER...Webber

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