Severe Thunderstorm Warning 104, NWS Salt Lake City, UT

Area Forecast Discussion
National Weather Service Salt Lake City UT
551 PM MDT Sat Aug 29 2026

.KEY MESSAGES, Issued 1151 AM MDT Sat Aug 29 2026...

- Multiple rounds of scattered showers and thunderstorms are
  expected to occur this afternoon across UT, primarily northern
  and central UT where strong to severe storms are expected.

- Flash flooding concerns exist across UT today through at least
  Monday. Of the days within this stretch, Monday looks to be the
  most concerning.

- Weather areawide may calm down somewhat by midweek, though some
  uncertainties remain regarding this solution.

&&

.DISCUSSION, Issued 1151 AM MDT Sat Aug 29 2026...
Currently, a deepening upper trough is pushing
inland with its axis centered over WA/OR with a shortwave to its
southeast progressing NE through the Great Basin. Ample mid-level
mass response has developed an enhanced belt of southwesterlies
atop strong mid-level frontogenesis, serving as a focal point for
thunderstorm development across northern UT this morning. A few
severe wind gusts have been observed primarily across the Great
Salt Lake Desert with sub-severe hail closer to the Wasatch Front,
though northeasterly winds and surface temperatures in the 60s
have largely limited the severe threat keeping storms elevated
instead of surface based due to a stable boundary layer. A few
stronger gusts can't be ruled out with this complex as it moves
further east into the Uinta basin where surface temperatures have
continually warmed this morning in the absence of cloud cover,
though gusts are not expected to be widespread.

Through the remainder of the afternoon, multiple shortwave
perturbations embedded within the flow will traverse northwest UT
serving as a focal point for thunderstorm development. Continual
moistening of the boundary layer with daytime heating increasing
with the erosion of a persistent cloud deck should result in
increasing instability generally south of a line extending from
Wendover to Salt Lake City yielding MLCAPE values from
1000-1500J/kg, perhaps higher if cloud cover clears faster.
Additionally, enhanced southwest flow aloft will result in Eff.
Shear values exceeding 40kts across a large portion of northern UT
to central UT, supporting the development of supercells capable of
wind gusts potentially in excess of 70mph and hail to around 1".

Flooding remains a concern today as well, particularly if more
supercellular convection develops given the moist environment
characterized by PWATs from 1-1.3" of water. However, this threat
may be limited by fast ENE storm motions today, though would still
pose a problem if storms are to track over problematic terrain and
burn scars.

Tomorrow, the upper trough progresses through ID serving as a
focal point for widespread thunderstorm development tomorrow
afternoon across UT. Moisture, instability, and shear leave much
to be desired, though portions of southern UT may see some flash
flood threat develop with slower moving storms associated with a
trailing wave. Come Monday, the threat for flash flooding across
southern UT increases substantially as a stronger moisture surge
races north. High PWATs, potentially as high as 1.3-1.5" of water
are expected to advect north amidst an environment favorable for
slow moving (and potentially backbuilding) storms. Some
uncertainties exist regarding this, though Monday is shaping up to
be quite wet across southern UT in particular.

&&

.AVIATION...

KSLC...Southerly winds are expected to prevail through the evening
and into the morning, with passing showers and thunderstorms causing
periodic gusty and erratic winds. The strongest storms will be
capable of producing heavy rainfall that may result in periods of
MVFR to IFR conditions.

REST OF UTAH AND SOUTHWEST WYOMING...For northern terminals,
widespread showers and thunderstorms are expected to persist through
the evening and into early morning before dissipating. The strongest
storms will be capable of producing gusty and erratic outflow winds
and heavy rainfall that may result in periods of MVFR to IFR
conditions. Southern terminals will remain gusty into early evening.

&&

.FIRE WEATHER, Issued 1226 PM MDT Sat Aug 29 2026...
Active weather continues today with strong to severe
thunderstorms developing this afternoon across northern and
central Utah with a flash flooding threat also developing this
afternoon across central and southern Utah. Regarding the severe
threat further north, wind gusts in excess of 58-70mph and hail to
around 1" are expected this afternoon with any of the stronger
storms that form. Across southern Utah, monsoonal moisture
continues to surge north bringing an attendant flash flooding
threat to the area through at least Monday. While storm
development across southern Utah may be somewhat muted Sunday
afternoon, Monday appears somewhat concerning regarding rainfall
high rainfall rates and amounts. Regardless, a wetting rain is
expected across the entirety of Utah through early next week.

Following this active patter, a drying and cooling trend will take
place as most showers and thunderstorms appear to remain confined
to the higher terrain at this time. Temperatures will run roughly
5F below seasonal normals with RH approaching normals around mid-
week.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Flood Watch through Monday evening for UTZ116>121-123>131.

WY...None.
&&

PUBLIC...Worster
AVIATION...Verzella
FIRE WEATHER...Worster

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

Special Weather Statement
National Weather Service Salt Lake City UT
535 PM MDT Sat Aug 29 2026

UTZ101-300015-
Great Salt Lake Desert and Mountains UT-
535 PM MDT Sat Aug 29 2026

...A strong thunderstorm will impact portions of south central Tooele
County through 615 PM MDT
...

At 535 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles southeast of Dugway Proving Ground Test Range, or 27 miles
southwest of Dugway English Village, moving east at 45 mph.

HAZARD...Wind gusts of 50 to 55 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Dugway English Village, Dugway Proving Ground Test Range, and Skull
Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3997 11330 4015 11336 4037 11270 4002 11261
TIME...MOT...LOC 2335Z 254DEG 40KT 4006 11321

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...55 MPH

JCW

Special Weather Statement
National Weather Service Salt Lake City UT
552 PM MDT Sat Aug 29 2026

UTZ128-131-300030-
South Central Utah UT-Glen Canyon Recreation Area/Lake Powell UT-
552 PM MDT Sat Aug 29 2026

...A strong thunderstorm will impact portions of south central
Garfield, south central San Juan and northeastern Kane Counties
through 630 PM MDT
...

At 552 PM MDT, Doppler radar was tracking a strong thunderstorm 20
miles southwest of Bullfrog, or 44 miles southeast of Escalante,
moving northeast at 35 mph.

HAZARD...Wind gusts of 50 to 55 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Halls Crossing, Ticaboo, and Bullfrog.

This includes Utah Route 276 between mile markers 33 and 34.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3719 11109 3747 11107 3760 11088 3764 11047
      3762 11047 3761 11053 3745 11053 3744 11062
      3738 11063 3738 11069 3731 11069 3730 11065
      3721 11064
TIME...MOT...LOC 2352Z 247DEG 31KT 3731 11102

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH

STW

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