Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 58, NWS Salt Lake City, UT

July 27, 2021Garfield County, Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 27, 2021, 1:23 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: Jul 27, 2021, 1:23 PM MDT (19:23 UTC)
Expired: Jul 27, 2021, 4:30 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), 168 km from the middle of the area, began a volume at 19:26 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, 7.4 hours before the alert went out and 249 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.

507 
WGUS55 KSLC 271923
FFWSLC
UTC017-055-272230-
/O.NEW.KSLC.FF.W.0058.210727T1923Z-210727T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

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 430 PM MDT.

* At 123 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across Pleasant Creek and Burro Wash. Between 0.5 and 1 
  inch of rain has fallen. Flash flooding is ongoing or expected to 
  begin shortly. Additional storm development is expected southward 
  to Sheets Gulch.

  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. Downstream flows along Pleasant Creek 
  and Sandy Creek are expected to continue through to the confluence 
  with the Fremont River draining through Caineville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3819 11118 3820 11115 3823 11112 3824 11112
      3829 11105 3833 11102 3833 11101 3821 11105
      3817 11104 3811 11107 3809 11110 3810 11116
      3815 11117 3817 11117

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

$$

SW

2 follow-up statements

324 
WGUS75 KSLC 272140
FFSSLC

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

UTC017-055-272230-
/O.CON.KSLC.FF.W.0058.000000T0000Z-210727T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
340 PM MDT Tue Jul 27 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM MDT THIS 
AFTERNOON FOR NORTHEASTERN GARFIELD AND SOUTH CENTRAL WAYNE 
COUNTIES...

At 340 PM MDT, the public reported flash flooding across portions of 
Capitol Reef National Park. Between 0.75 and 1.5 inches of rain have 
fallen across the upper headwaters of the Pleasant Creek drainage. 
Flash flooding is already occurring. Additional storms are moving 
into the Sheets Gulch and Five Mile Wash areas.

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. Downstream flows along Pleasant Creek 
  and Sandy Creek are expected to continue through to the confluence 
  with the Fremont River draining through Caineville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3819 11118 3820 11115 3823 11112 3824 11112
      3829 11105 3833 11102 3833 11101 3821 11105
      3817 11104 3811 11107 3809 11110 3810 11116
      3815 11117 3817 11117

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

$$

SW

434 
WGUS75 KSLC 272226
FFSSLC

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

UTC017-055-272236-
/O.EXP.KSLC.FF.W.0058.000000T0000Z-210727T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
426 PM MDT Tue Jul 27 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 430 PM MDT THIS AFTERNOON FOR 
NORTHEASTERN GARFIELD AND SOUTH CENTRAL WAYNE COUNTIES...

The heavy rain has ended. Flash flooding was observed across various 
portions of Capitol Reef National Park, however, flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3819 11118 3820 11115 3823 11112 3824 11112
      3829 11105 3833 11102 3833 11101 3821 11105
      3817 11104 3811 11107 3809 11110 3810 11116
      3815 11117 3817 11117

$$

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, 12:35 PM MDT	Flash Flood Warning Considerable damage threat	SLC	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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.