Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 67, NWS Salt Lake City, UT

July 29, 2021Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 29, 2021, 7:46 PM MDT for Kane 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 29, 2021, 7:46 PM MDT (01:46 UTC)
Expired
Jul 29, 2021, 10:45 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Kane County, UT

The radar

The Cedar City radar (KICX), 121 km from the middle of the area, began a volume at 01:45 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

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 1.8 hours before the alert went out and 205 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, Flgstf/Belemont, AZ at 00:00Z on 2021-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 222 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 00:00Z on 2021-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
222 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
1896 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

659 
WGUS55 KSLC 300146
FFWSLC
UTC025-300445-
/O.NEW.KSLC.FF.W.0067.210730T0146Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
746 PM MDT Thu Jul 29 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 1045 PM MDT.

* At 746 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over Coyote Creek. Between 0.75 and 1.5 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly in Coyote Creek and into Wahweap Creek.

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

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams.

* Some locations that will experience flash flooding include...
  Coyote Creek and Wahweap Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3700 11168 3705 11183 3724 11191 3725 11183
      3719 11164 3700 11145 3700 11151 3700 11157
      3700 11162 3700 11163

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

$$

MT
2 follow-up statements
382 
WGUS75 KSLC 300322
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
922 PM MDT Thu Jul 29 2021

UTC025-300445-
/O.CON.KSLC.FF.W.0067.000000T0000Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
922 PM MDT Thu Jul 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM MDT THIS 
EVENING FOR SOUTH CENTRAL KANE COUNTY...

At 922 PM MDT, Doppler radar indicated thunderstorms that brought up 
to 1.5 inches of rain to Buckskin Gulch. Flash flooding is ongoing 
or expected to begin shortly, traveling down Buckskin Gulch into the 
Paria 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...
  Buckskin Gulch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3700 11168 3705 11183 3724 11191 3725 11183
      3719 11164 3700 11145 3700 11151 3700 11157
      3700 11162 3700 11163

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

$$

MT
811 
WGUS75 KSLC 300440
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
1040 PM MDT Thu Jul 29 2021

UTC025-300450-
/O.EXP.KSLC.FF.W.0067.000000T0000Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
1040 PM MDT Thu Jul 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1045 PM MDT THIS EVENING FOR 
SOUTH CENTRAL KANE COUNTY...

The heavy rain has ended over Coyote Creek and Wahweap Creek. 
Flooding is no longer expected to pose a threat. Runoff from earlier 
heavy rain will continue to gradually recede through late this 
evening. Please continue to heed any road closures.

A Flash Flood Watch remains in effect until 300 AM MDT for a portion 
of southern Utah.

LAT...LON 3700 11168 3705 11183 3724 11191 3725 11183
      3719 11164 3700 11145 3700 11151 3700 11157
      3700 11162 3700 11163

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 6:03 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield117 min
Jul 29, 6:03 PM MDTSpecial Weather StatementSLCKane27 min
Jul 29, 6:24 PM MDTSpecial Weather StatementSLCKane36 min
Jul 29, 7:06 PM MDTSpecial Weather StatementSLCWashington24 min
Jul 29, 7:16 PM MDTSpecial Weather StatementSLCWayne29 min
Jul 29, 7:23 PM MDTSpecial Weather StatementSLCWayne37 min
Jul 29, 7:40 PM MDTFlash Flood Warning Considerable damage threatSLCKane3 hr
Jul 29, 7:41 PM MDTSevere Thunderstorm WarningSLCGarfield, Wayne34 min
Jul 29, 7:52 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne113 min
Jul 29, 8:11 PM MDTSpecial Weather StatementSLCIron19 min
Jul 29, 8:51 PM MDTSpecial Weather StatementSLCIron39 min
Jul 29, 9:01 PM MDTFlash Flood Warning Considerable damage threatSLCWashington3 hr
Jul 29, 9:42 PM MDTSpecial Weather StatementSLCCarbon63 min
Jul 30, 3:38 AM MDTFlash Flood WatchSLCBeaver, Garfield, Iron, Kane, Piute, Washington and 1 more19 hr
Jul 30, 2:17 PM MDTFlash Flood Warning Considerable damage threatSLCWashington3 hr
Jul 30, 2:18 PM MDTSpecial Weather StatementSLCSevier42 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.