Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 68, NWS Salt Lake City, UT

July 29, 2021Garfield County, Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 29, 2021, 7:52 PM MDT for Garfield County, Wayne County, Utah. It was in force for 113 min. 1 report 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: Jul 29, 2021, 7:52 PM MDT (01:52 UTC)
Expired: Jul 29, 2021, 9:45 PM MDT
In force: 113 min
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties 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 01:56 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

Time	Report	Where	Remark
Jul 29, 8:30 PM MDT	FLASH FLOOD	7 S Capitol Reef Np, UT	5 INCHES OF DEBRIS, MUD, AND GRAVEL OVERFLOWING THE SCENIC DRIVE BY CAPITOL GORGE AREA. FLOWING WATER IN A USUALLY DRY WASH AT THE END OF THE SCENIC DRIVE. SCENIC DRIVE IS CLOSED AT GRAND WASH FOR THE TIME BEING.

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 00:00Z, 1.9 hours before the alert went out and 258 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: 407 J/kg
Mixed-layer CIN: -168 J/kg
Mixed-layer LCL: 2854 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

541 
WGUS55 KSLC 300152
FFWSLC
UTC017-055-300345-
/O.NEW.KSLC.FF.W.0068.210730T0152Z-210730T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Northeastern Garfield County in southern Utah...
  South Central Wayne County in southern Utah...

* Until 945 PM MDT.

* At 752 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across portions of Capitol Reef National Park. The 
  expected rainfall rate is 1 to 2 inches in 1 hour. Flash flooding 
  is ongoing or expected to begin shortly in Capitol Gorge, Sandy 
  Creek, Pleasant Creek, Sulphur Creek, and Oak 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...
  Capitol Reef National Park.

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 3821 11129 3826 11113 3815 11109 3810 11125

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

MT

2 follow-up statements

335 
WGUS75 KSLC 300247
FFSSLC

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

UTC017-055-300345-
/O.CON.KSLC.FF.W.0068.000000T0000Z-210730T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
847 PM MDT Thu Jul 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM MDT THIS 
EVENING FOR NORTHEASTERN GARFIELD AND SOUTH CENTRAL WAYNE COUNTIES...

At 847 PM MDT, Doppler radar indicated thunderstorms that moved 
through portions of Capitol Reef National Park produced up to one 
inch of rain. This rain is likely producing flash flooding in parts 
of the park including Capitol Gorge, Sandy Creek, Pleasant Creek, 
Sulphur Creek, and Oak 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...
  Capitol Reef National Park.

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 3821 11129 3826 11113 3815 11109 3810 11125

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

MT

476 
WGUS75 KSLC 300340
FFSSLC

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

UTC017-055-300350-
/O.EXP.KSLC.FF.W.0068.000000T0000Z-210730T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
940 PM MDT Thu Jul 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 945 PM MDT THIS EVENING FOR 
NORTHEASTERN GARFIELD AND SOUTH CENTRAL WAYNE COUNTIES...

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

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

LAT...LON 3821 11129 3826 11113 3815 11109 3810 11125

$$

MT

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, 7:40 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	3 hr
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, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.