Alert archive / Utah / Flash Flood Warnings in 2026

Flash Flood Warning 121, NWS Salt Lake City, UT

September 12, 2026Garfield County, Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 12, 2026, 3:34 PM MDT for Garfield County, Wayne County, Utah. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 12, 2026, 3:34 PM MDT (21:34 UTC)
Expired
Sep 12, 2026, 6:30 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Garfield County, UT, Wayne County, UT

The radar

The Cedar City radar (KICX), 166 km from the middle of the area, began a volume at 21:36 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 9.6 hours before the alert went out and 294 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Salt Lake City I, UT at 12:00Z on 2026-09-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Salt Lake City I, UT at 12:00Z on 2026-09-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
11 J/kg
Mixed-layer CIN
-385 J/kg
Mixed-layer LCL
2556 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
54 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

961 
WGUS55 KSLC 122134
FFWSLC
UTC017-055-130030-
/O.NEW.KSLC.FF.W.0121.260912T2134Z-260913T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
334 PM MDT Sat Sep 12 2026

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Northeastern Garfield County in southern Utah...
  South Central Wayne County in southern Utah...

* Until 630 PM MDT.

* At 334 PM MDT, Doppler radar indicated thunderstorms producing
  heavy rain across portions of Capitol Reef National Park...
  specifically Pleasant Creek, Burro Wash, Cottonwood Wash, Five Mile
  Wash, and Sheets Gulch. Between 0.25 and 0.5 inches of rain have
  fallen. Additional rainfall amounts up to 0.25 inches are possible
  in the warned area. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms producing
           flash flooding.

  SOURCE...Radar indicated.

  IMPACT...Life threatening flash flooding of creeks, normally dry
           washes, and slot canyons

* Some locations that will experience flash flooding include...
  Capitol Reef National Park

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away or be swept away. River banks and culverts can become
unstable and unsafe.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, dry washes, and slot canyons which can
become killers in heavy rains. Campers and hikers should avoid these
areas.

&&

LAT...LON 3815 11127 3818 11129 3821 11114 3821 11113
      3825 11114 3827 11110 3834 11101 3834 11100
      3823 11105 3817 11104 3809 11107 3809 11121

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

GM
1 follow-up statement
893 
WGUS75 KSLC 122311
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
511 PM MDT Sat Sep 12 2026

UTC017-055-130030-
/O.CON.KSLC.FF.W.0121.000000T0000Z-260913T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
511 PM MDT Sat Sep 12 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM MDT THIS
EVENING FOR NORTHEASTERN GARFIELD AND SOUTH CENTRAL WAYNE COUNTIES...

At 511 PM MDT, Doppler radar indicated thunderstorms producing heavy
rain across portions of Capitol Reef National Park...specifically
Pleasant Creek, Burro Wash, Cottonwood Wash, Five Mile Wash, and
Sheets Gulch. Between 0.5 and 1 inches of rain have fallen. Flash
flooding is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar indicated.

IMPACT...Life threatening flash flooding of creeks, normally dry
         washes, and slot canyons

Some locations that will experience flash flooding include...
  Capitol Reef National Park

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away or be swept away. River banks and culverts can become
unstable and unsafe.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, dry washes, and slot canyons which can
become killers in heavy rains. Campers and hikers should avoid these
areas.

&&

LAT...LON 3815 11127 3818 11129 3821 11114 3821 11113
      3825 11114 3827 11110 3834 11101 3834 11100
      3823 11105 3817 11104 3809 11107 3809 11121

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Webber

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Salt Lake City, UT wrote its last area forecast discussion before this flash flood warning went out at Sep 12, 2:03 PM MDT, 1 hour 31 minutes earlier.

Area forecast discussion, Sep 12, 2:03 PM MDT, 1 hour 31 minutes before
Area Forecast Discussion
National Weather Service Salt Lake City UT
203 PM MDT Sat Sep 12 2026

.KEY MESSAGES, Issued 1159 AM MDT Sat Sep 12 2026...

- An isolated flash flood threat will persist as moisture remains
  in place across primarily southeastern Utah.

- Breezy southwesterly winds will develop Saturday and Sunday
  afternoons, with gusts up to 35 mph on Saturday and up to 40 mph
  on Sunday ahead of a cold front. The highest wind gusts are
  expected across western valleys and in Uinta Co., WY.

&&

.DISCUSSION, Issued 1159 AM MDT Sat Sep 12 2026...
Southwesterly flow will continue to strengthen
across the region ahead of a trough currently pushing into the
PacNW. Gusts this afternoon are expected to reach up to 35 mph
across typically prone areas such as western valleys south of I-80
and across Uinta Co., WY. Tomorrow, as this trough approaches,
southwest flow will further increase though still remain under
advisory criteria around 40 mph in these same areas. High-res
guidance suggests an initial boundary will develop across northern
Utah as a distant shortwave trough rotates through the mid-level
low, which will result in somewhat lighter, westerly flow around
the Salt Lake Valley northward. As a stronger shortwave passes
through the main low Sunday evening and overnight, this will bring
the main cold front through northern and central Utah, resulting
in colder temperatures and a switch to gusty northwesterly winds.
Monday highs will reach 5-10 degrees below normal across northern
areas (near normal across central/southern Utah).

Lingering moisture across southeastern Utah will result in
isolated thunderstorms developing this afternoon between mainly
Lake Powell up into the Uinta Basin. Given that this moisture is
relatively shallow in the mid-levels, the main threat will be
gusty outflow winds, with just an isolated flash flood threat
given any training storms over a sensitive area. Southwest flow
will potentially draw a bit more moisture over the state on
Sunday, however model guidance shows higher uncertainty in the
magnitude of this moisture. Similar to today, the flash flood
threat will still remain fairly isolated despite slightly higher
spatial coverage of storms, particularly considering quicker
storm motions.

The cold front will struggle to scour the moisture out of
southeastern Utah as it dissipates partway through the state, thus
expect isolated to scattered showers and thunderstorms to develop
each afternoon this week. Across the rest of the area, expect dry
conditions and gradually warming temperatures.

Uncertainty increases greatly by mid-week, with potential for
another shortwave trough drawing moisture northward across Utah
late Wednesday into Thursday. Around 30% of ensemble members
suggest this shortwave does not develop, which would likely yield
quieter conditions.

&&

.AVIATION, Issued 1159 AM MDT Sat Sep 12 2026...

KSLC...Light and variable winds currently across the terminal are
expected to transition to a prevailing northwest around 19z. A
normal diurnal wind switch is once again expected between 02-03z,
with increasingly gusty southerly winds developing late night/Sunday
morning in advance of a cold front. Frontal passage is expected to
switch winds back to northwest between 19-21z. VFR conditions will
continue to hold.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected to
prevail across the airspace throughout the valid TAF period. Gusty
southerly winds are expected today, largely focused across southern
and eastern portions. Isolated showers and thunderstorms are
expected this afternoon and evening across southern and southeastern
Utah, but will dissipate with loss of solar input this evening.

&&

.FIRE WEATHER...Lingering moisture across southern and eastern Utah
will result in isolated to scattered showers and thunderstorms
Sunday afternoon, with gusty outflow winds and moderate-heavy rain
being the main threats. Large-scale southwesterly winds will
continue to strengthen ahead of a cold front, with gusts up to 40
mph possible across western valleys. A dry cold front will then
move through northern and central Utah before dissipating late
Sunday into early Monday morning. This front will bring a quick
transition to briefly gusty northwesterly winds alongside cooler
temperatures, particularly further north.

Through at least Wednesday, expect a gradual warming trend with
most areas seeing little to no precipitation. Given moisture
hanging on across southeastern Utah, these areas still could see
isolated showers and thunderstorms each afternoon. Additionally,
minimum RH will remain elevated across much of southern and
eastern Utah, exceeding 30 percent in most areas. Western valleys,
especially further north, may continue to see minimum RH in the
upper teens with good overnight recoveries.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

PUBLIC...Cunningham
AVIATION...Merrill
FIRE WEATHER...Cunningham

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

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 11, 9:14 PM MDTSpecial Weather StatementSLCGarfield46 min
Sep 11, 9:37 PM MDTSpecial Weather StatementSLC53 min
Sep 11, 10:34 PM MDTSpecial Weather StatementSLCWayne41 min
Sep 11, 11:13 PM MDTSpecial Weather StatementSLCWayne32 min
Sep 11, 11:39 PM MDTSpecial Weather StatementSLC51 min

Nearby

Flash Flood Warnings in Utah, 2026Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.