Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 66, NWS Salt Lake City, UT

July 29, 2021Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 29, 2021, 7:40 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, 7:40 PM MDT (01:40 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), 97 km from the middle of the area, began a volume at 01:39 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, 1.7 hours before the alert went out and 202 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: 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.

255 
WGUS55 KSLC 300140
FFWSLC
UTC025-300445-
/O.NEW.KSLC.FF.W.0066.210730T0140Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
740 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 740 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over Buckskin Gulch. Between 0.75 and 1.5 inches of 
  rain have fallen. 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.

* 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 11205 3712 11210 3714 11207 3700 11185
      3700 11200 3700 11203

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

$$

MT

2 follow-up statements

035 
WGUS75 KSLC 300321
FFSSLC

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

UTC025-300445-
/O.CON.KSLC.FF.W.0066.000000T0000Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
921 PM MDT Thu Jul 29 2021

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

At 921 PM MDT, Doppler radar indicated thunderstorms that produced 
up to 1.5 inches of rain at Coyote Creek. 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,
         urban areas, highways, streets and underpasses.

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 11205 3712 11210 3714 11207 3700 11185
      3700 11200 3700 11203

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

$$

MT

938 
WGUS75 KSLC 300438
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
1038 PM MDT Thu Jul 29 2021

UTC025-300448-
/O.EXP.KSLC.FF.W.0066.000000T0000Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
1038 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 the Buckskin Gulch area. Flooding is 
no longer expected to pose a threat. Runoff from earlier heavy rain 
will continue to gradually recede through late this evening.

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

LAT...LON 3700 11205 3712 11210 3714 11207 3700 11185
      3700 11200 3700 11203

$$

LC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 6:03 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	117 min
Jul 29, 6:03 PM MDT	Special Weather Statement	SLC	Kane	27 min
Jul 29, 6:24 PM MDT	Special Weather Statement	SLC	Kane	36 min
Jul 29, 7:06 PM MDT	Special Weather Statement	SLC	Washington	24 min
Jul 29, 7:16 PM MDT	Special Weather Statement	SLC	Wayne	29 min
Jul 29, 7:23 PM MDT	Special Weather Statement	SLC	Wayne	37 min
Jul 29, 7:41 PM MDT	Severe Thunderstorm Warning	SLC	Garfield, Wayne	34 min
Jul 29, 7:46 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	3 hr
Jul 29, 7:52 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield, Wayne	113 min
Jul 29, 8:11 PM MDT	Special Weather Statement	SLC	Iron	19 min
Jul 29, 8:51 PM MDT	Special Weather Statement	SLC	Iron	39 min
Jul 29, 9:01 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Washington	3 hr
Jul 29, 9:42 PM MDT	Special Weather Statement	SLC	Carbon	63 min
Jul 30, 3:38 AM MDT	Flash Flood Watch	SLC	Beaver, Garfield, Iron, Kane, Piute, Washington and 1 more	19 hr
Jul 30, 2:17 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Washington	3 hr
Jul 30, 2:18 PM MDT	Special Weather Statement	SLC	Sevier	42 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.