Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 39, NWS Salt Lake City, UT

July 24, 2021Garfield County, Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 24, 2021, 1:34 PM MDT for Garfield County, Kane County, Utah. It was in force for 4 hr. 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 24, 2021, 1:34 PM MDT (19:34 UTC)
Expired: Jul 24, 2021, 5:30 PM MDT
In force: 4 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Garfield County, UT, Kane County, UT

The radar

The Cedar City radar (KICX), 70 km from the middle of the area, began a volume at 19:33 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 24, 4:00 PM MDT	FLASH FLOOD	5 Se Bryce Cyn Np, UT	VIDEO SHOWING SIGNIFICANT FLOWS THROUGH A NORMALLY DRY WASH JUST SOUTH OF TROPIC. VIDEO SHOWS A MATURE FULLY GROWN TREE FLOATING BENEATH AN UNDERPASS ALONG BRYCE HIGHWAY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 7.6 hours before the alert went out and 261 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1053 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: -9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

464 
WGUS55 KSLC 241934
FFWSLC
UTC017-025-242330-
/O.NEW.KSLC.FF.W.0039.210724T1934Z-210724T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
134 PM MDT Sat Jul 24 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southern Garfield County in southern Utah...
  North Central Kane County in southern Utah...

* Until 530 PM MDT.

* At 134 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 2.5 inches of 
  rain have fallen. 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,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Bryce Canyon National Park, Tropic and Cannonville.

This includes the following highways...
	Utah Route 12 between mile markers 21 and 26.

This includes the following streams and drainages...
  Bryce Creek draining into the Paria River and areas downstream 
  along the Paria River through Kodachrome Basin State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3755 11205 3758 11206 3761 11207 3761 11209
      3759 11217 3762 11217 3766 11214 3766 11213
      3765 11211 3763 11207 3761 11205 3759 11205
      3755 11204 3752 11204 3751 11203 3748 11201
      3742 11203 3742 11204 3749 11203 3752 11205

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

$$

SW

2 follow-up statements

108 
WGUS75 KSLC 242214
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
414 PM MDT Sat Jul 24 2021

UTC017-025-242330-
/O.CON.KSLC.FF.W.0039.000000T0000Z-210724T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
414 PM MDT Sat Jul 24 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MDT THIS 
AFTERNOON FOR SOUTHERN GARFIELD AND NORTH CENTRAL KANE COUNTIES...

At 414 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 2.5 inches of rain have 
fallen. 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,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Bryce Canyon National Park, Tropic and Cannonville.

This includes the following highways...
	Utah Route 12 between mile markers 21 and 26.

This includes the following streams and drainages...
  Bryce Creek draining into the Paria River and areas downstream 
  along the Paria River through Kodachrome Basin State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3755 11205 3758 11206 3761 11207 3761 11209
      3759 11217 3762 11217 3766 11214 3766 11213
      3765 11211 3763 11207 3761 11205 3759 11205
      3755 11204 3752 11204 3751 11203 3748 11201
      3742 11203 3742 11204 3749 11203 3752 11205

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

$$

SW

786 
WGUS75 KSLC 242326
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
526 PM MDT Sat Jul 24 2021

UTC017-025-242336-
/O.EXP.KSLC.FF.W.0039.000000T0000Z-210724T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
526 PM MDT Sat Jul 24 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 530 PM MDT THIS AFTERNOON FOR 
SOUTHERN GARFIELD AND NORTH CENTRAL KANE COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed any road closures. Runoff from 
earlier heavy rainfall will continue to diminish through the evening 
hours.

LAT...LON 3755 11205 3758 11206 3761 11207 3761 11209
      3759 11217 3762 11217 3766 11214 3766 11213
      3765 11211 3763 11207 3761 11205 3759 11205
      3755 11204 3752 11204 3751 11203 3748 11201
      3742 11203 3742 11204 3749 11203 3752 11205

$$

SW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 6:14 PM MDT	Areal Flood Advisory	SLC	Washington	61 min
Jul 24, 3:23 AM MDT	Flash Flood Watch	SLC	Beaver, Garfield, Iron, Kane, Piute, Washington and 1 more	42 hr
Jul 24, 12:56 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	3 hr
Jul 24, 12:58 PM MDT	Special Weather Statement	SLC	Kane	32 min
Jul 24, 2:13 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Washington	3 hr
Jul 24, 2:24 PM MDT	Severe Thunderstorm Warning	SLC	Washington	21 min
Jul 24, 3:16 PM MDT	Severe Thunderstorm Warning	SLC	Washington	29 min
Jul 24, 3:40 PM MDT	Severe Thunderstorm Warning	SLC	Iron, Washington	35 min
Jul 24, 4:04 PM MDT	Severe Thunderstorm Warning	SLC	Washington	26 min
Jul 24, 4:07 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane, Washington	3 hr
Jul 24, 4:12 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Iron, Washington	3 hr
Jul 24, 4:30 PM MDT	Severe Thunderstorm Warning	SLC	Washington	30 min
Jul 24, 5:24 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Washington	3 hr

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.