Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 132, NWS Salt Lake City, UT

September 11, 2021Emery County, Garfield County, Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 11, 2021, 6:19 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
Sep 11, 2021, 6:19 PM MDT (00:19 UTC)
Expired
Sep 11, 2021, 9:30 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

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

The radar

The Cedar City radar (KICX), 159 km from the middle of the area, began a volume at 00:20 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, 0.3 hours before the alert went out and 259 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 2021-09-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 207 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 2021-09-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -61 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
207 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
3403 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-61 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

092 
WGUS55 KSLC 120019
FFWSLC
UTC015-017-055-120330-
/O.NEW.KSLC.FF.W.0132.210912T0019Z-210912T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
619 PM MDT Sat Sep 11 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 930 PM MDT.

* At 619 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 normally dry
           washes, roads and low water crossings.

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

This includes the following highways...
	Utah Route 12 between mile markers 115 and 117...and
	between mile markers 120 and 122.
	Utah Route 24 between mile markers 70 and 92.

This warning includes Spring Canyon, Sulphur Creek, Grand Wash and 
Capitol Gorge.  This also includes the Scenic Drive in Capitol Reef 
National Park.

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 3817 11133 3841 11147 3850 11126 3823 11103
      3812 11119

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

$$

CRK
2 follow-up statements
616 
WGUS75 KSLC 120229
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
829 PM MDT Sat Sep 11 2021

UTC015-120239-
/O.CAN.KSLC.FF.W.0132.000000T0000Z-210912T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Emery UT-
829 PM MDT Sat Sep 11 2021

...FLASH FLOOD WARNING IS CANCELLED FOR EMERY COUNTY...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

LAT...LON 3817 11133 3841 11147 3850 11126 3823 11103
      3812 11119

$$

UTC017-055-120330-
/O.CON.KSLC.FF.W.0132.000000T0000Z-210912T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
829 PM MDT Sat Sep 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM MDT THIS 
EVENING FOR NORTHEASTERN GARFIELD AND WESTERN WAYNE COUNTIES...

At 829 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 normally dry
         washes, roads and low water crossings.

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

This warning includes Spring Canyon, Sulphur Creek, Grand Wash and 
Capitol Gorge.  This also includes the Scenic Drive in Capitol Reef 
National Park.

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 3817 11133 3841 11147 3850 11126 3823 11103
      3812 11119

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

$$

CRK
417 
WGUS75 KSLC 120321
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
921 PM MDT Sat Sep 11 2021

UTC017-055-120331-
/O.EXP.KSLC.FF.W.0132.000000T0000Z-210912T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
921 PM MDT Sat Sep 11 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 930 PM MDT THIS EVENING FOR 
NORTHEASTERN GARFIELD AND WESTERN WAYNE COUNTIES...

Occasional showers and thunderstorms with brief heavy rainfall will 
be possible into the late evening, however the threat of flash 
flooding has ended.

LAT...LON 3817 11133 3841 11147 3850 11126 3823 11103
      3812 11119

$$

CRK

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 11, 6:30 PM MDTSpecial Weather StatementSLCJuab45 min
Sep 11, 7:16 PM MDTSpecial Weather StatementSLCJuab44 min
Sep 11, 7:24 PM MDTSpecial Weather StatementSLC51 min
Sep 11, 8:15 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne3 hr
Sep 11, 8:22 PM MDTSpecial Weather StatementSLCSanpete38 min
Sep 11, 9:06 PM MDTSpecial Weather StatementSLCSanpete39 min
Sep 12, 3:29 PM MDTSpecial Weather StatementSLCBox Elder46 min
Sep 12, 3:37 PM MDTSevere Thunderstorm WarningSLCBox Elder23 min
Sep 12, 3:54 PM MDTSevere Thunderstorm WarningSLCBox Elder51 min
Sep 12, 4:13 PM MDTSpecial Weather StatementSLCBox Elder47 min
Sep 12, 4:31 PM MDTSevere Thunderstorm WarningSLCBox Elder44 min
Sep 12, 4:42 PM MDTSevere Thunderstorm WarningSLCBox Elder24 min
Sep 12, 5:08 PM MDTSevere Thunderstorm WarningSLCBox Elder20 min
Sep 12, 5:14 PM MDTSpecial Weather StatementSLC46 min
Sep 12, 5:54 PM MDTSevere Thunderstorm WarningSLCBox Elder51 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.