Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 135, NWS Salt Lake City, UT

September 28, 2021Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 28, 2021, 3:10 PM MDT for Wayne County, Utah. It was in force for 3 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
Sep 28, 2021, 3:10 PM MDT (21:10 UTC)
Expired
Sep 28, 2021, 6:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Wayne County, UT

The radar

The Cedar City radar (KICX), 162 km from the middle of the area, began a volume at 21:11 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
Sep 28, 3:30 PM MDTFLASH FLOOD5 S Capitol Reef Np, UTCAPITOL GORGE FLASH FLOOD. SCENIC ROAD OVERTOPPED WITH DEEP WATER, MUD AND WAS CLOSED OVER 24 HOURS. SEVERAL VEHICLES STUCK AND REQUIRED TOWING TO REMOVE. WATER/MUD ALSO FLOWED OVER SR24 EAST OF THE HICKMAN BRIDGE TRAILHEAD.

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 12:00Z, 9.2 hours before the alert went out and 255 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, Grand Junction, CO at 12:00Z on 2021-09-28Temperature 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, Grand Junction, CO at 12:00Z on 2021-09-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2319 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
112 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

791 
WGUS55 KSLC 282110
FFWSLC
UTC055-290015-
/O.NEW.KSLC.FF.W.0135.210928T2110Z-210929T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
310 PM MDT Tue Sep 28 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 615 PM MDT.

* At 310 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain in Capitol Reef National Park. Between 0.5 and 1 inch 
  of rain has 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...
  Capitol Gorge and the Grand Wash in Capitol Reef National Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3815 11122 3826 11128 3830 11114 3820 11110

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

$$

LC
2 follow-up statements
735 
WGUS75 KSLC 282256
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
456 PM MDT Tue Sep 28 2021

UTC055-290015-
/O.CON.KSLC.FF.W.0135.000000T0000Z-210929T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
456 PM MDT Tue Sep 28 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MDT THIS 
EVENING FOR SOUTH CENTRAL WAYNE COUNTY...

At 456 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain in Capitol Reef National Park. Between 0.75 and 1.5 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...
  Capitol Gorge and the Grand Wash in Capitol Reef National Park.

This includes the following highways...
	Utah Route 24 between mile markers 84 and 88.

Mud and/or running water have been reported in Capitol Gorge and 
near mile marker 84 on highway 24.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3815 11122 3826 11128 3830 11114 3820 11110

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

$$

LC
201 
WGUS75 KSLC 290010
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
610 PM MDT Tue Sep 28 2021

UTC055-290020-
/O.EXP.KSLC.FF.W.0135.000000T0000Z-210929T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
610 PM MDT Tue Sep 28 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 615 PM MDT THIS EVENING FOR 
SOUTH CENTRAL WAYNE COUNTY...

The heavy rain has ended within Capitol Reef National Park. 
Additional flash flooding is no longer expected. Water from earlier 
heavy rain and flooding will continue to gradually recede this 
evening. Please continue to heed remaining road closures.

LAT...LON 3815 11122 3826 11128 3830 11114 3820 11110

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 27, 6:10 PM MDTSpecial Weather StatementSLCKane35 min
Sep 27, 7:59 PM MDTSpecial Weather StatementSLCIron46 min
Sep 28, 10:46 AM MDTWind AdvisorySLCBox Elder, Salt Lake, Tooele, Utah10 hr

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.