Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
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814
FXUS65 KSLC 291959
AFDSLC
Area Forecast Discussion
National Weather Service Salt Lake City UT
159 PM MDT Wed Jul 29 2026
.KEY MESSAGES...
- Scattered showers and thunderstorms moving across the forecast
area through the remainder of the day will bring an increased
threat of heavy rainfall and flash flooding before conditions
dry out substantially by Thursday.
- There is a high chance that temperatures will become extremely
hot by the weekend as the ridge continues to build, bring the
potential for an increase in heat related illness.
- An active northern storm track is expected to bring an increase
in southwest winds late this weekend. There is a low to moderate
(30-50%) chance of critical fire weather conditions developing
Sunday and Monday afternoon.
&&
.DISCUSSION...Two waves of energy can be noted on satellite
analysis this afternoon; one across northeast Utah/ southwest
Wyoming and one across southwestern Utah. For the northern area,
this shortwave is fairly worked over, with stratiform rain and
isolated thunderstorms translating through the Uinta Mountains and
Uinta County, WY. The southern shortwave, however, continues to
produce a concentrated area of strong showers and thunderstorms as
it continues to march northward. A moisture rich near-surface
environment and stout synoptic support for lift will continue to
support a threat of flash flooding under this area of showers and
thunderstorms. This area of storms is expected to track northeast
through the remainder of the evening, with the eastern side of the
disturbance looking like the primary focus area for stronger
convection. As the northeastern Utah wave continues its track
northeast as well, northern Utah will then move out of the
subsident wake which will assist with development of showers and
thunderstorms across Utah`s West Desert. Isolated storms are
expected to progress into the Wasatch Front through the evening,
mainly the northern portions, and bring potential for strong
outflow winds in excess of 40 mph.
By Thursday, a much drier air mass will build into the area and
cut off nearly all chances for showers and thunderstorms across
the forecast area. Locations which may continue to see isolated
shower and thunderstorm activity will be the Uinta Mountains,
where high elevation surface heating may tap into high-based
instability associated with the departing mid-level moisture.
Otherwise, anticipate a cumulus field to develop over the high
terrain through the afternoon hours. There`s generally a low
chance (10% or less) that these clouds develop into showers,
but if it`s going to happen, it`ll happen over the central Utah
mountains. That said, there will be a much lower chance for heavy
rainfall and flash flooding. By Friday, moisture will be hard to
find over the area as surface relative humidity falls into the
single digits to low-teens across the entire area alongside a near
zero chance for showers.
In addition to the drier air mass, a significant warming trend is
expected across the entirety of the forecast area. Each day from
Thursday through Saturday, daytime highs are expected to increase
by 3-5 degrees with overnight low temperatures following suit. By
Friday, temperatures along the Wasatch Front will climb back to
the triple digit mark with overnight lows only falling into the
low- to mid-70s. For the lower elevations of southern Utah (lower
Washington County/ Glen Canyon area), high temperatures will bump
into the low-110s with overnight lows only dropping into the
upper-70s to low-80s. As such, a litany of heat headlines
(extreme heat watches, warnings, and heat advisories) have been
issued and will go into effect starting at noon on Friday.
An active northern jet stream over the PacNW and northern Rockies
region late in the weekend is expected to help bring an increase
in southwest winds across a portion of Utah. Pairing with the very
hot and very dry conditions, these increasingly breezy southwest
winds will bring elevated to near-critical fire weather
conditions across southwest, west-central, and northeast Utah on
Sunday and Monday afternoon. A dry cold front is anticipated to
move into northern Utah and southwest Wyoming Sunday night into
Monday, bringing at least some relief from heat. If enough
northwest flow develops in the wake of this potential cold front,
we may begin to see impacts from wildfire smoke originating the
Columbia Basin as we head into the first half of next week.
&&
.AVIATION...
KSLC...Breezy south winds are expected to remain in place over the
KSLC terminal alongside VFR conditions. That said, there is around
a 30% chance for showers and thunderstorms to impact the terminal
around 23Z, bringing strong outflow wind gusts and potential
reduction of VIS due to blowing dust. Storm threat around the
terminal is expected to diminish by around 04Z, with winds
remaining light out of the south through the overnight hours.
REST OF UTAH AND SOUTHWEST WYOMING...An area of showers and
thunderstorms will progress across southern and central Utah
through the remainder of the afternoon and evening, bringing
potential for MVFR conditions due to CIG and VIS reductions in
areas of heavy rainfall. Showers and thunderstorms are also
expected to develop across Utah`s West Desert after 21-22Z,
bringing potential for gusty and erratic outflow wind gusts along
the Wasatch Front between 01-03Z. Showers and thunderstorms will
diminish through the evening hours, with VFR conditions and
terrain driven flows expected overnight.
&&
.FIRE WEATHER...One final moisture surge moves across Utah through
the remainder of today, allowing for scattered shower and
thunderstorm development across a majority of Utah. Under stronger
storms, heavy rainfall and frequent lightning are expected. With
drier air in place over far northern Utah, any storms developing
in this region will be capable of outflow wind gusts in excess of
40 mph.
As we move into Thursday, a significant drying of the air mass is
expected as high pressure repositions nearly overhead. Afternoon
relative humidity is expected to fall by upwards of 10 percent in
the western area and by as much as 30 percent in the eastern area.
A less significant day of drying is expected, however, relative
humidity is expected to drop into the single digits to low-teens
across a majority of Utah (including the high terrain features) by
Friday. Alongside this significant drying trend, a significant
warming trend is also expected. High temperatures in the lower
elevation areas across western and eastern Utah will be reaching
into the low- to mid-100s, with temperatures as high as 112-114 in
the lowest elevations of southern Utah. Adding to the very hot
and very dry conditions, an active storm track to our north is
anticipated to dip far enough south by late this weekend to bring
an increase in southwest winds. There is currently a low to medium
chance (30-50% probability) for critical fire weather conditions
to develop over a portion of west-central, southwest, and
northeast Utah on Sunday and Monday. Thereafter, hot and dry
conditions will remain in place through at least the middle
of next week.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Heat Advisory from noon Saturday to 9 PM MDT Sunday for UTZ101-
115-116-120>122.
Extreme Heat Watch from Saturday afternoon through Sunday
evening for UTZ102-104>106-114.
Extreme Heat Warning from noon Friday to 9 PM MDT Sunday for
UTZ123-124-128>131.
WY...None.
&&
$$
PUBLIC...Webber
AVIATION...Webber
FIRE WEATHER...Webber
For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity