Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 137, NWS Salt Lake City, UT

October 5, 2021Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Oct 5, 2021, 4:43 PM MDT for 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
Oct 5, 2021, 4:43 PM MDT (22:43 UTC)
Expired
Oct 5, 2021, 8:45 PM MDT
In force
4 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), 98 km from the middle of the area, began a volume at 22:44 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

TimeReportWhereRemark
Oct 5, 6:30 PM MDTFLASH FLOOD19 W Big Water, UTFLASH FLOOD WAVE OF 1000 CFS WAS OBSERVED ON THE PARIA AT KANAB USGS GAGE BY 6PM LOCAL TIME, WITH MULTIPLE SMALLER FLOOD WAVES FOLLOWING. A SINGLE LARGE FLOOD WAVE OF 3K CFS WAS OBSERVED FAR DOWNSTREAM AT LEES FERRY BY 1130PM WITH BUCKSKIN GULCH LIKELY FLASHIN

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, 10.7 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 12:00Z on 2021-10-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-10-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 121 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
986 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

860 
WGUS55 KSLC 052243
FFWSLC
UTC025-060245-
/O.NEW.KSLC.FF.W.0137.211005T2243Z-211006T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
443 PM MDT Tue Oct 5 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 845 PM MDT.

* At 443 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across Wire Pass and Upper Buckskin Gulch areas. 
  Between 0.25 and 0.5 inches of rain have fallen. Additional 
  rainfall is expected over the next few hours. 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 normally dry washes
           and slot canyons.

* Some locations that will experience flash flooding include...
  House Rock Road, Wire Pass, and Buckskin Gulch

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for flooding even in locations not receiving rain. Dry 
washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

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 3712 11206 3709 11180 3700 11181 3700 11211

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

$$

GM
2 follow-up statements
997 
WGUS75 KSLC 060046
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
646 PM MDT Tue Oct 5 2021

UTC025-060245-
/O.CON.KSLC.FF.W.0137.000000T0000Z-211006T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
646 PM MDT Tue Oct 5 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM MDT THIS 
EVENING FOR SOUTHERN KANE COUNTY...

At 646 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned 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 normally dry washes
         and slot canyons.

Some locations that will experience flash flooding include...
  House Rock Road, Wire Pass, and Buckskin Gulch

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for flooding even in locations not receiving rain. Dry 
washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

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 3712 11206 3709 11180 3700 11181 3700 11211

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

$$

CRK
216 
WGUS75 KSLC 060241
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
841 PM MDT Tue Oct 5 2021

UTC025-060251-
/O.EXP.KSLC.FF.W.0137.000000T0000Z-211006T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
841 PM MDT Tue Oct 5 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 845 PM MDT THIS EVENING FOR 
SOUTHERN KANE COUNTY...

The heavy rain has ended. Slot canyons and normally dry washes will 
continue to see elevated flows through the overnight hours.

LAT...LON 3712 11206 3709 11180 3700 11181 3700 11211

$$

CRK

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 5, 3:07 PM MDTSpecial Weather StatementSLCWashington38 min
Oct 5, 3:40 PM MDTSpecial Weather StatementSLCWashington50 min
Oct 5, 4:01 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington4 hr
Oct 5, 4:03 PM MDTSpecial Weather StatementSLCKane42 min
Oct 5, 5:42 PM MDTSpecial Weather StatementSLCKane48 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.