Severe Thunderstorm Warning 102, NWS Salt Lake City, UT

Area Forecast Discussion
National Weather Service Salt Lake City UT
1226 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, Issued 1216 PM MDT Sat Aug 29 2026...

KSLC...Southerly winds will vie with northerlies with passing
showers and thunderstorms this afternoon into early evening.
Widespread storms are expected to redevelop across northern Utah
after 22z and are expected to impact the terminal at times through
the remainder of the evening. Storms this afternoon will be capable
of producing gusty and erratic outflow winds in excess of 50 kts,
hail, and heavy rainfall that may result in periods of MVFR to IFR
conditions.

REST OF UTAH AND SOUTHWEST WYOMING...Widespread showers and
thunderstorms have redeveloped across much of the airspace and are
expected to persist through this evening. Storms this afternoon
will be capable of producing gusty and erratic outflow winds in
excess of 50 kts, hail, and heavy rainfall that may result in
periods of MVFR to IFR conditions, mainly across northern Utah.

&&

.FIRE WEATHER...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...None.
WY...None.
&&

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

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

Preliminary Local Storm Report
National Weather Service Salt Lake City UT
456 PM MDT Sat Aug 29 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0330 PM     Tstm Wnd Gst     1 SSE Sugarville        39.45N 112.64W
08/29/2026  M60 MPH          Millard            UT   Mesonet

            Measured at the Sutherland - Agrimet SUTU
            site.

&&

AD

Preliminary Local Storm Report
National Weather Service Salt Lake City UT
458 PM MDT Sat Aug 29 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0458 PM     Flash Flood      4 NW Goblin Valley      38.58N 110.75W
08/29/2026                   Emery              UT   Park/Forest Srvc

            Chute Canyon is actively flashing.

&&

CRK

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

UTZ106-111-113-292345-
Wasatch Plateau/Book Cliffs UT-Utah Valley UT-
Wasatch Mountains South of I-80 UT-
501 PM MDT Sat Aug 29 2026

...A strong thunderstorm will impact portions of western Wasatch and
central Utah Counties through 545 PM MDT
...

At 500 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles north of Elberta, or 11 miles west of Payson, moving east at 35
mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch 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...
Provo, Payson, Spanish Fork, Springville, Mapleton, Salem, Elk Ridge,
Woodland Hills, Brigham Young University, Palmyra, Benjamin, Lake
Shore, Utah Lake, West Mountain, Spring Lake, Elberta, and Genola.

This includes the following highways...
 Interstate 15 between mile markers 248 and 266.
 US Route 6 between mile markers 174 and 185.

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 4002 11133 4000 11205 4016 11205 4032 11139
TIME...MOT...LOC 2300Z 256DEG 29KT 4009 11194

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

JCW

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

UTZ101-115-300000-
Western Millard and Juab Counties UT-
Great Salt Lake Desert and Mountains UT-
508 PM MDT Sat Aug 29 2026

...A strong thunderstorm will impact portions of northwestern Juab
and southwestern Tooele Counties through 600 PM MDT
...

At 507 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles west of Partoun, or 34 miles east of Schellbourne, moving east
at 45 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch 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...
Partoun, Fish Springs Wildlife Refuge, Dugway Proving Ground Test
Range, Callao, and Trout Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

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 4003 11338 3976 11327 3959 11404 3981 11405
TIME...MOT...LOC 2307Z 249DEG 39KT 3969 11404

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

JCW

Preliminary Local Storm Report
National Weather Service Salt Lake City UT
518 PM MDT Sat Aug 29 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0430 PM     Tstm Wnd Gst     1 SSE Sugarville        39.45N 112.64W
08/29/2026  M60 MPH          Millard            UT   Mesonet

            Corrects previous tstm wnd gst report from 1
            SSE Sugarville. Added 1 hour to the
            previously reported time. Measured at the
            Sutherland - Agrimet SUTU site.

&&

AD

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

UTZ111-113-115>118-300000-
Sanpete Valley UT-Western Millard and Juab Counties UT-
Wasatch Plateau/Book Cliffs UT-Central Mountains UT-
Eastern Juab/Millard Counties UT-Wasatch Mountains South of I-80 UT-
521 PM MDT Sat Aug 29 2026

...A strong thunderstorm will impact portions of northeastern
Sanpete, east central Juab, northwestern Emery, west central Carbon
and south central Utah Counties through 600 PM MDT
...

At 521 PM MDT, Doppler radar was tracking a strong thunderstorm near
Nephi, moving east at 45 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch 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...
Nephi, Scofield, Fairview, Fountain Green, Levan, Milburn, Clear
Creek, and Indianola.

This includes the following highways...
 Interstate 15 between mile markers 211 and 228.
 US Route 89 between mile markers 280 and 298.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3953 11205 3968 11209 3992 11121 3959 11113
TIME...MOT...LOC 2321Z 257DEG 40KT 3962 11189

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

JCW