Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 7, NWS Salt Lake City, UT

July 13, 2021Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 13, 2021, 2:14 PM MDT for 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
Jul 13, 2021, 2:14 PM MDT (20:14 UTC)
Expired
Jul 13, 2021, 5:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Wayne County, UT

The radar

The Cedar City radar (KICX), 150 km from the middle of the area, began a volume at 20:17 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.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 8.2 hours before the alert went out and 271 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, Grand Junction, CO at 12:00Z on 2021-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2021-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.193958Sfc1 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
27 J/kg
Mixed-layer CIN
-350 J/kg
Mixed-layer LCL
3436 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
184 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

242 
WGUS55 KSLC 132014
FFWSLC
UTC055-132315-
/O.NEW.KSLC.FF.W.0007.210713T2014Z-210713T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
214 PM MDT Tue Jul 13 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  West Central Wayne County in southern Utah...

* Until 515 PM MDT.

* At 214 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.75 and 1.25 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly in the headwaters of the Sand Creek Wash to the confluence 
  of Sulfur Creek and through the town of Torrey. Additionally, 
  flows are expected out of Sunglow Canyon near the town of Bicknell.

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

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Bicknell and Torrey.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3842 11147 3838 11142 3833 11136 3831 11136
      3829 11138 3830 11155 3834 11156 3838 11153

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

$$

SW
2 follow-up statements
377 
WGUS75 KSLC 132219
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
419 PM MDT Tue Jul 13 2021

UTC055-132315-
/O.CON.KSLC.FF.W.0007.000000T0000Z-210713T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
419 PM MDT Tue Jul 13 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM MDT THIS 
AFTERNOON FOR WEST CENTRAL WAYNE COUNTY...

At 419 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 2 inches of rain have 
fallen in the upper headwaters of the Sand Creek Wash. Flash 
flooding is ongoing or expected to begin shortly. This water is 
expected to continue flowing through the Sand Creek Wash downstream 
toward Sulphur Creek.

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

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Bicknell and Torrey.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3842 11147 3838 11142 3833 11136 3831 11136
      3829 11138 3830 11155 3834 11156 3838 11153

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

$$

SW
792 
WGUS75 KSLC 132311
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
511 PM MDT Tue Jul 13 2021

UTC055-132321-
/O.EXP.KSLC.FF.W.0007.000000T0000Z-210713T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
511 PM MDT Tue Jul 13 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 515 PM MDT THIS AFTERNOON FOR 
WEST CENTRAL WAYNE COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1200 AM MDT Wednesday 
for portions of southern Utah and southwest Utah.

LAT...LON 3842 11147 3838 11142 3833 11136 3831 11136
      3829 11138 3830 11155 3834 11156 3838 11153

$$

SW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 3:03 PM MDTFlash Flood Warning Considerable damage threatSLCWayne3 hr
Jul 13, 3:28 PM MDTSpecial Weather StatementSLCCarbon32 min
Jul 13, 4:50 PM MDTSpecial Weather StatementSLCBeaver40 min
Jul 13, 5:17 PM MDTSpecial Weather StatementSLCBeaver, Millard43 min

Nearby

Flash Flood Warnings in Utah, 2021Every flash flood warning in 2021

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.