Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 82, NWS Salt Lake City, UT

August 1, 2021Emery County, Garfield County, Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 1, 2021, 6:01 PM MDT for Emery County, 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
Aug 1, 2021, 6:01 PM MDT (00:01 UTC)
Expired
Aug 1, 2021, 9:00 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Emery County, UT, Garfield County, UT, Wayne County, UT

The radar

The Grand Junction radar (KGJX), 175 km from the middle of the area, began a volume at 00:03 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 00:00Z, 0.0 hours before the alert went out and 154 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 00:00Z on 2021-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 162 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 00:00Z on 2021-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 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
162 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
2258 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

524 
WGUS55 KSLC 020001
FFWSLC
UTC015-017-055-020300-
/O.NEW.KSLC.FF.W.0082.210802T0001Z-210802T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
601 PM MDT Sun Aug 1 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southeastern Emery County in central Utah...
  Northeastern Garfield County in southern Utah...
  Eastern Wayne County in southern Utah...

* Until 900 PM MDT.

* At 601 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across 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 creeks and streams,
           normally dry washes, highways, and slot canyons.

* Some locations that will experience flash flooding include...
  mainly rural areas of Southeastern Emery, Northeastern Garfield 
  and Eastern Wayne Counties

This includes the following highways...
Utah Route 95 between mile markers 6 and 24 as well as Poison 
Springs Canyon, Moonshine Wash, and additional tributaries of the 
Dirty Devil River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for flooding even in locations not receiving rain. Dry 
washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3878 11038 3877 11009 3875 11008 3875 11010
      3873 11011 3871 11011 3871 11009 3869 11010
      3868 11009 3867 11009 3867 11007 3866 11007
      3866 11006 3862 11006 3861 11007 3860 11006
      3845 11005 3802 11029 3806 11081

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

$$

CRK
2 follow-up statements
646 
WGUS75 KSLC 020129
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
729 PM MDT Sun Aug 1 2021

UTC015-017-055-020300-
/O.CON.KSLC.FF.W.0082.000000T0000Z-210802T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Emery UT-Garfield UT-Wayne UT-
729 PM MDT Sun Aug 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING 
FOR SOUTHEASTERN EMERY, NORTHEASTERN GARFIELD AND EASTERN WAYNE 
COUNTIES...

At 729 PM MDT, Heavy rain has fallen across 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 creeks and streams,
         normally dry washes, highways, and slot canyons.

Some locations that will experience flash flooding include...
  mainly rural areas of Southeastern Emery, Northeastern Garfield 
  and Eastern Wayne Counties

This includes the following highways...
Utah Route 95 between mile markers 6 and 24 as well as Poison 
Springs Canyon, Moonshine Wash, and additional tributaries of the 
Dirty Devil River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for flooding even in locations not receiving rain. Dry 
washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3878 11038 3877 11009 3875 11008 3875 11010
      3873 11011 3871 11011 3871 11009 3869 11010
      3868 11009 3867 11009 3867 11007 3866 11007
      3866 11006 3862 11006 3861 11007 3860 11006
      3845 11005 3802 11029 3806 11081

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

$$

CRK
717 
WGUS75 KSLC 020256
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
856 PM MDT Sun Aug 1 2021

UTC015-017-055-020306-
/O.EXP.KSLC.FF.W.0082.000000T0000Z-210802T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Emery UT-Garfield UT-Wayne UT-
856 PM MDT Sun Aug 1 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR 
SOUTHEASTERN EMERY, NORTHEASTERN GARFIELD AND EASTERN WAYNE 
COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Elevated runoff will continue in area slot canyons, normally 
dry washes and streams through late tonight.

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

LAT...LON 3878 11038 3877 11009 3875 11008 3875 11010
      3873 11011 3871 11011 3871 11009 3869 11010
      3868 11009 3867 11009 3867 11007 3866 11007
      3866 11006 3862 11006 3861 11007 3860 11006
      3845 11005 3802 11029 3806 11081

$$

CRK

The office that day

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

IssuedProductOfficeCountiesLasted
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, 2:30 PM MDTFlash Flood Warning Considerable damage threatSLCWayne4 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.