Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 57, NWS Salt Lake City, UT

July 27, 2021Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 27, 2021, 12:35 PM MDT for Wayne County, Utah. It was in force for 3 hr. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 27, 2021, 12:35 PM MDT (18:35 UTC)
Expired: Jul 27, 2021, 3:30 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), 164 km from the middle of the area, began a volume at 18:35 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.

What was reported inside it

Time	Report	Where	Remark
Jul 27, 12:54 PM MDT	FLASH FLOOD	1 S Fruita, UT	FLOODING ACROSS ROADWAY ON THE SCENIC DRIVE, CAPITOL REEF NATIONAL PARK.
Jul 27, 1:30 PM MDT	FLASH FLOOD	1 S Fruita, UT	UPDATED LSR TO REFLECT CLOSURE OF SCENIC DRIVE. FLOODING ACROSS ROADWAY ON THE SCENIC DRIVE, CAPITOL REEF NATIONAL PARK.
Jul 27, 2:15 PM MDT	FLASH FLOOD	Fruita, UT	FLASH FLOODING IN GRAND WASH AND ACROSS RT 24. MUDDY DEBRIS HEAVY FLOW ALSO REPORTED IN SULPHUR CREEK.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 6.6 hours before the alert went out and 253 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 28 J/kg
Mixed-layer CIN: -304 J/kg
Mixed-layer LCL: 1735 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: -20 m²/s²
0-3 km storm-relative helicity: -8 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

825 
WGUS55 KSLC 271835
FFWSLC
UTC055-272130-
/O.NEW.KSLC.FF.W.0057.210727T1835Z-210727T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
1235 PM MDT Tue Jul 27 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 330 PM MDT.

* At 1235 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across tributaries leading into the Fremont River, 
  Sulphur Creek, and Pleasant Creek. Between 0.5 and 1 inch of rain 
  has fallen within 30 minutes. Flash flooding is ongoing or 
  expected to begin shortly.

  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...
  Capitol Reef National Park and Fruita, specifically tributaries 
  leading into the Fremont River and Sulphur Creek. Additional flows 
  in tributaries leading into Pleasant Creek are also expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3820 11129 3824 11132 3830 11132 3831 11128
      3829 11120 3830 11115 3828 11110 3830 11105
      3829 11104 3829 11105 3824 11112 3823 11112
      3820 11115 3819 11118 3818 11123 3818 11128

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

$$

SW

2 follow-up statements

807 
WGUS75 KSLC 271930
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
130 PM MDT Tue Jul 27 2021

UTC055-272130-
/O.CON.KSLC.FF.W.0057.000000T0000Z-210727T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
130 PM MDT Tue Jul 27 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM MDT THIS 
AFTERNOON FOR SOUTH CENTRAL WAYNE COUNTY...

At 130 PM MDT, the public reported flash flooding across the Scenic 
Drive. Between 0.5 and 1.5 inches of rain have fallen in the past 
hour over tributaries leading into the Fremont River, Pleasant 
Creek, and Sulphur Creek. Flash flooding is already occurring.

HAZARD...Life threatening flash flooding. Heavy rain producing
         flash flooding.

SOURCE...Public reported.

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

Some locations that will experience flash flooding include...
  Capitol Reef National Park and Fruita, specifically tributaries 
  leading into the Fremont River and Sulphur Creek. Additional flows 
  in tributaries leading into Pleasant Creek are also expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3820 11129 3824 11132 3830 11132 3831 11128
      3829 11120 3830 11115 3828 11110 3830 11105
      3829 11104 3829 11105 3824 11112 3823 11112
      3820 11115 3819 11118 3818 11123 3818 11128

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

SW

765 
WGUS75 KSLC 272127
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
327 PM MDT Tue Jul 27 2021

UTC055-272137-
/O.EXP.KSLC.FF.W.0057.000000T0000Z-210727T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
327 PM MDT Tue Jul 27 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 330 PM MDT THIS AFTERNOON FOR 
SOUTH CENTRAL WAYNE COUNTY...

The heavy rain has ended. Earlier flash flooding was reported along 
the Scenic Drive, Grand Wash, Sulphur Creek, and portions of US-24. 
Runoff from earlier heavy rainfall will continue to decrease through 
the afternoon hours. Flooding is no longer expected to pose a threat 
at this time. Additional heavy rainfall may be possible through the 
remainder of the afternoon and evening. Please continue to heed 
remaining road closures.

LAT...LON 3820 11129 3824 11132 3830 11132 3831 11128
      3829 11120 3830 11115 3828 11110 3830 11105
      3829 11104 3829 11105 3824 11112 3823 11112
      3820 11115 3819 11118 3818 11123 3818 11128

$$

SW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 26, 6:39 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	3 hr
Jul 26, 7:08 PM MDT	Special Weather Statement	SLC	Salt Lake	37 min
Jul 27, 1:23 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield, Wayne	3 hr
Jul 27, 1:55 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	3 hr
Jul 27, 2:46 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield, Kane	3 hr
Jul 27, 4:40 PM MDT	Special Weather Statement	SLC	Rich	50 min

Nearby

Flash Flood Warnings in Utah, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.