Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 60, NWS Salt Lake City, UT

July 27, 2021Garfield County, Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 27, 2021, 2:46 PM MDT for Garfield County, 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 27, 2021, 2:46 PM MDT (20:46 UTC)
Expired
Jul 27, 2021, 5:45 PM MDT
In force
3 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), 143 km from the middle of the area, began a volume at 20:48 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 12:00Z, 8.8 hours before the alert went out and 266 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 12:00Z on 2021-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 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 12:00Z on 2021-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 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
36 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
901 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
84 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

324 
WGUS55 KSLC 272046
FFWSLC
UTC017-025-272345-
/O.NEW.KSLC.FF.W.0060.210727T2046Z-210727T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
246 PM MDT Tue Jul 27 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 545 PM MDT.

* At 246 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the upper basin of Twentyfive Mile Wash and 
  upper basin of Coyote Gulch. Between 1 and 1.5 inches of rain have 
  fallen near Twentyfive Mile Wash and up to 0.5 inches near 
  Peekaboo Slot Canyon. Additional heavy rainfall is anticipated 
  across this 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 creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Twentyfive Mile Wash, Harris Wash, Egypt Slot Canyons, Peekaboo 
  Slot Canyon, and Spooky Slot Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3755 11133 3756 11136 3764 11137 3767 11127
      3767 11121 3766 11119 3761 11117 3759 11113
      3758 11113 3747 11118 3747 11121 3749 11126

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

$$

SW
2 follow-up statements
517 
WGUS75 KSLC 272221
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
421 PM MDT Tue Jul 27 2021

UTC017-025-272345-
/O.CON.KSLC.FF.W.0060.000000T0000Z-210727T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
421 PM MDT Tue Jul 27 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM MDT THIS 
AFTERNOON FOR SOUTH CENTRAL GARFIELD AND NORTHEASTERN KANE 
COUNTIES...

At 421 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the upper basin of Twentyfive Mile Wash and upper basin 
of Coyote Gulch. Between 1.25 and 1.75 inches of rain have fallen 
near Twentyfive Mile Wash and 0.5 to 1.0 inch have fallen near 
Peekaboo Slot Canyon. Additional heavy rainfall is anticipated 
across this 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 creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Twentyfive Mile Wash, Harris Wash, Egypt Slot Canyons, Peekaboo 
  Slot Canyon, and Spooky Slot Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3755 11133 3756 11136 3764 11137 3767 11127
      3767 11121 3766 11119 3761 11117 3759 11113
      3758 11113 3747 11118 3747 11121 3749 11126

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

$$

SW
844 
WGUS75 KSLC 272343
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
543 PM MDT Tue Jul 27 2021

UTC017-025-272353-
/O.EXP.KSLC.FF.W.0060.000000T0000Z-210727T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
543 PM MDT Tue Jul 27 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 545 PM MDT THIS AFTERNOON FOR 
SOUTH CENTRAL GARFIELD AND NORTHEASTERN KANE COUNTIES...

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

LAT...LON 3755 11133 3756 11136 3764 11137 3767 11127
      3767 11121 3766 11119 3761 11117 3759 11113
      3758 11113 3747 11118 3747 11121 3749 11126

$$

SW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 26, 6:39 PM MDTFlash Flood Warning Considerable damage threatSLCKane3 hr
Jul 26, 7:08 PM MDTSpecial Weather StatementSLCSalt Lake37 min
Jul 27, 12:35 PM MDTFlash Flood Warning Considerable damage threatSLCWayne3 hr
Jul 27, 1:23 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne3 hr
Jul 27, 1:55 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield3 hr
Jul 27, 4:40 PM MDTSpecial Weather StatementSLCRich50 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.