Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 8, NWS Salt Lake City, UT

July 13, 2021Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 13, 2021, 3:03 PM MDT for Wayne County, Utah. It was in force for 3 hr. 1 report 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 13, 2021, 3:03 PM MDT (21:03 UTC)
Expired: Jul 13, 2021, 6:00 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), 162 km from the middle of the area, began a volume at 21:05 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 13, 4:05 PM MDT	FLASH FLOOD	Capitol Reef Np, UT	FLASH FLOOD REPORTED IN A DRY WASH LEADING INTO SULPHUR CREEK NEAR THE PARK VISITOR CENTER. THE WATER ROSE 2 FEET.

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, 9.1 hours before the alert went out and 256 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: 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.

282 
WGUS55 KSLC 132103
FFWSLC
UTC055-140000-
/O.NEW.KSLC.FF.W.0008.210713T2103Z-210714T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Salt Lake City has issued a

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

* Until 600 PM MDT.

* At 303 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 0.75 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly, specifically for Sulfur Creek within Capitol Reef 
  National Park into the Freemont River.

  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, Fruita and Caineville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3833 11136 3835 11134 3836 11134 3837 11131
      3835 11125 3832 11121 3831 11116 3834 11100
      3827 11102 3823 11123 3826 11132 3828 11135
      3829 11136

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

$$

SW

2 follow-up statements

498 
WGUS75 KSLC 132225
FFSSLC

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

UTC055-140000-
/O.CON.KSLC.FF.W.0008.000000T0000Z-210714T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
425 PM MDT Tue Jul 13 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING 
FOR SOUTH CENTRAL WAYNE COUNTY...

At 425 PM MDT, between 0.5 and 1.00 inches of rain have fallen 
within the Sulphur Creek basin. Flash flooding is ongoing or 
expected to begin shortly. Flash flooding is expected to continue 
through Sulphur Creek into the Fremont River and areas downstream.

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

SOURCE...National Park Rangers have reported flash flooding in
         tributaries of Sulphur Creek

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, Fruita and Caineville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3833 11136 3835 11134 3836 11134 3837 11131
      3835 11125 3832 11121 3831 11116 3834 11100
      3827 11102 3823 11123 3826 11132 3828 11135
      3829 11136

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

$$

SW

737 
WGUS75 KSLC 140005
FFSSLC

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

UTC055-140015-
/O.EXP.KSLC.FF.W.0008.000000T0000Z-210714T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
605 PM MDT Tue Jul 13 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTH CENTRAL WAYNE COUNTY...

The heavy rain has ended. Flash flooding was observed in a dry wash 
leading into Sulphur Creek near the visitor center of Capitol Reef 
National Park, with smaller flows noted through Sulphur Creek. 
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 for portions 
of southern Utah and southwest Utah.

LAT...LON 3833 11136 3835 11134 3836 11134 3837 11131
      3835 11125 3832 11121 3831 11116 3834 11100
      3827 11102 3823 11123 3826 11132 3828 11135
      3829 11136

$$

SW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 13, 2:14 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Wayne	3 hr
Jul 13, 3:28 PM MDT	Special Weather Statement	SLC	Carbon	32 min
Jul 13, 4:50 PM MDT	Special Weather Statement	SLC	Beaver	40 min
Jul 13, 5:17 PM MDT	Special Weather Statement	SLC	Beaver, Millard	43 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.