Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 86, NWS Salt Lake City, UT

August 2, 2021Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 2, 2021, 2:30 PM MDT for Wayne County, Utah. It was in force for 4 hr. 2 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
Aug 2, 2021, 2:30 PM MDT (20:30 UTC)
Expired
Aug 2, 2021, 6:30 PM MDT
In force
4 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 20:30 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

TimeReportWhereRemark
Aug 2, 4:36 PM MDTFLASH FLOOD2 Sw Capitol Reef Np, UTCAPITOL REEF OFFICIALS REPORT FLASH FLOODING IN GRAND WASH.
Aug 2, 5:18 PM MDTFLASH FLOOD3 W Capitol Reef Np, UTPARK SERVICE REPORTS THE FREMONT RIVER IS FLASHING AND SULPHUR CREEK IS RUNNING HIGH.

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, 8.5 hours before the alert went out and 255 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 2021-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 22 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 2021-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.1939Sfc1 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
22 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
1085 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

114 
WGUS55 KSLC 022030
FFWSLC
UTC055-022330-
/O.NEW.KSLC.FF.W.0086.210802T2030Z-210802T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
230 PM MDT Mon Aug 2 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southwestern Wayne County in southern Utah...

* Until 530 PM MDT.

* At 230 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.25 and 0.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.25 to 0.5 
  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.

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

* Some locations that will experience flash flooding include...
  Capitol Reef National Park, Torrey, Teasdale and Fruita.

This includes the following streams and drainages...
  Sulphur Creek, Grand Wash, Capitol Gorge, Pleasant Creek, and the 
  Fremont River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3833 11131 3833 11124 3831 11111 3832 11105
      3828 11103 3824 11110 3820 11109 3818 11111
      3818 11130 3825 11148 3832 11150 3833 11139

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

$$

MPS
3 follow-up statements
340 
WGUS75 KSLC 022204
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
404 PM MDT Mon Aug 2 2021

UTC055-022330-
/O.CON.KSLC.FF.W.0086.000000T0000Z-210802T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
404 PM MDT Mon Aug 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MDT THIS 
AFTERNOON FOR SOUTHWESTERN WAYNE COUNTY...

At 404 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 0.5 and 1 inch of rain has 
fallen. 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 slot canyons, small
         streams, and normally dry washes.

Some locations that will experience flash flooding include...
  Capitol Reef National Park, Torrey, Teasdale and Fruita.

This includes the following streams and drainages...
  Sulphur Creek, Grand Wash, Capitol Gorge, Pleasant Creek, and the 
  Fremont River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3833 11131 3833 11124 3831 11111 3832 11105
      3828 11103 3824 11110 3820 11109 3818 11111
      3818 11130 3825 11148 3832 11150 3833 11139

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

$$

MPS
607 
WGUS55 KSLC 022326
FFWSLC
UTC055-030030-
/O.EXT.KSLC.FF.W.0086.000000T0000Z-210803T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
526 PM MDT Mon Aug 2 2021

The National Weather Service in Salt Lake City has extended the

* Flash Flood Warning for...
  Southwestern Wayne County in southern Utah...

* Until 630 PM MDT.

* At 526 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. 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 small streams and
           normally dry washes.

* Some locations that will experience flash flooding include...
  Grand Wash and the Fremont River within Capitol Reef National Park.

This includes the following highways...
	Utah Route 12 between mile markers 115 and 122.
	Utah Route 24 between mile markers 65 and 95.

Capitol Reef National Park Rangers reported normally dry washes are 
still flowing and the Fremont River remains very high. Thus the 
Flash Flood Warning is being extended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3833 11131 3833 11124 3831 11111 3832 11105
      3828 11103 3824 11110 3820 11109 3818 11111
      3818 11130 3825 11148 3832 11150 3833 11139

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

$$

MPS
493 
WGUS75 KSLC 030025
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
625 PM MDT Mon Aug 2 2021

UTC055-030035-
/O.EXP.KSLC.FF.W.0086.000000T0000Z-210803T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
625 PM MDT Mon Aug 2 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 630 PM MDT THIS EVENING FOR 
SOUTHWESTERN WAYNE COUNTY...

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

A Flash Flood Watch remains in effect until 900 PM MDT for portions 
of Utah and southwest Wyoming.

LAT...LON 3833 11131 3833 11124 3831 11111 3832 11105
      3828 11103 3824 11110 3820 11109 3818 11111
      3818 11130 3825 11148 3832 11150 3833 11139

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 6:01 PM MDTFlash Flood Warning Considerable damage threatSLCEmery, Garfield, Wayne3 hr
Aug 1, 6:09 PM MDTSevere Thunderstorm WarningSLCBox Elder, Tooele51 min
Aug 1, 6:17 PM MDTSpecial Weather StatementSLCBox Elder43 min
Aug 1, 6:27 PM MDTAreal Flood AdvisorySLCTooele3 hr
Aug 1, 6:36 PM MDTSpecial Weather StatementSLCSalt Lake39 min
Aug 1, 6:47 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake, Tooele43 min
Aug 1, 7:00 PM MDTAreal Flood AdvisorySLCSalt Lake3 hr
Aug 1, 7:07 PM MDTAreal Flood AdvisorySLCGarfield, Iron113 min
Aug 1, 7:25 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake35 min
Aug 1, 7:41 PM MDTAreal Flood AdvisorySLCSalt Lake3 hr
Aug 1, 7:58 PM MDTFlash Flood Warning Considerable damage threatSLCDavis3 hr
Aug 1, 8:25 PM MDTAreal Flood AdvisorySLCDavis3 hr
Aug 1, 8:51 PM MDTAreal Flood AdvisorySLCUtah114 min
Aug 1, 9:06 PM MDTAreal Flood AdvisorySLCDavis, Weber3 hr
Aug 2, 2:04 AM MDTFlash Flood WatchSLCBeaver, Box Elder, Cache, Carbon, Davis, Duchesne and 19 more18 hr
Aug 2, 1:16 PM MDTFlash Flood Warning Considerable damage threatSLCCarbon3 hr
Aug 2, 1:27 PM MDTFlash Flood Warning Considerable damage threatSLCEmery3 hr
Aug 2, 2:56 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne3 hr
Aug 2, 3:24 PM MDTSevere Thunderstorm WarningSLCGarfield66 min
Aug 2, 3:32 PM MDTSpecial Weather StatementSLCEmery43 min
Aug 2, 3:52 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield4 hr
Aug 2, 4:00 PM MDTSpecial Weather StatementSLCJuab45 min
Aug 2, 4:14 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, San Juan3 hr
Aug 2, 4:25 PM MDTSpecial Weather StatementSLC50 min
Aug 2, 4:55 PM MDTSpecial Weather StatementSLC50 min
Aug 2, 5:22 PM MDTSpecial Weather StatementSLCBox Elder38 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.