Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 51, NWS Salt Lake City, UT

July 26, 2021Iron County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 26, 2021, 2:35 PM MDT for Iron County, Utah. It was in force for 115 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 26, 2021, 2:35 PM MDT (20:35 UTC)
Expired
Jul 26, 2021, 4:30 PM MDT
In force
115 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Iron County, UT

The radar

The Cedar City radar (KICX), 25 km from the middle of the area, began a volume at 20:36 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
Jul 26, 2:42 PM MDTFLASH FLOODCedar City, UTWATER IS FLOWING ONTO MANY ROADWAYS IN CEDAR CITY, INCLUDING ON INTERSTATE 15 NEAR MILE MARKER 59.

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

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 8.6 hours before the alert went out and 259 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, Las Vegas, NV at 12:00Z on 2021-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 467 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2021-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 square meters per square second.193958Sfc1 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
467 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1095 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

125 
WGUS55 KSLC 262035
FFWSLC
UTC021-262230-
/O.NEW.KSLC.FF.W.0051.210726T2035Z-210726T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
235 PM MDT Mon Jul 26 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southeastern Iron County in southern Utah...

* Until 430 PM MDT.

* At 235 PM MDT, Doppler radar indicated thunderstorms producing 
  intense rain in Cedar City. Between 0.75 and 1.75 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly. Basement flooding, flows on roads, and potential road 
  closures

  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...
  Cedar City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3771 11318 3771 11306 3768 11305 3764 11309
      3764 11318

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

$$

GM
2 follow-up statements
165 
WGUS75 KSLC 262106
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
306 PM MDT Mon Jul 26 2021

UTC021-262230-
/O.CON.KSLC.FF.W.0051.000000T0000Z-210726T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-
306 PM MDT Mon Jul 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM MDT THIS 
AFTERNOON FOR SOUTHEASTERN IRON COUNTY...

At 306 PM MDT, Flash Flooding has been observed on SR 56 west of 
Cedar City. Widespread ponding of water has also occurred in parking 
lots and other roadways in town. Flash Flooding is ongoing. Between 
1 and 2.25 inches of rain have fallen. The heaviest rainfall has 
ended, but additional light to periodic moderate rain is possible.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Trained weather spotters reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Cedar City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3771 11318 3771 11306 3768 11305 3764 11309
      3764 11318

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

GM
880 
WGUS75 KSLC 262228
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
428 PM MDT Mon Jul 26 2021

UTC021-262238-
/O.EXP.KSLC.FF.W.0051.000000T0000Z-210726T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-
428 PM MDT Mon Jul 26 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 430 PM MDT THIS AFTERNOON FOR 
SOUTHEASTERN IRON COUNTY...

The heavy rain has ended. Additional flooding is no longer expected 
to pose a threat, but waters will only gradually recede over the 
next few hours for those areas impacted by the earlier floods. 
Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1200 AM MDT Tuesday for 
portions of southern Utah and southwest Utah.

LAT...LON 3771 11318 3771 11306 3768 11305 3764 11309
      3764 11318

$$

GM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 6:06 PM MDTSpecial Weather StatementSLCWashington39 min
Jul 25, 6:16 PM MDTSpecial Weather StatementSLCWashington44 min
Jul 26, 3:37 AM MDTFlash Flood WatchSLCBeaver, Garfield, Iron, Kane, Piute, Washington and 1 more20 hr
Jul 26, 1:13 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington3 hr
Jul 26, 1:37 PM MDTSevere Thunderstorm WarningSLCWashington23 min
Jul 26, 1:40 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield3 hr
Jul 26, 1:47 PM MDTSpecial Weather StatementSLCPiute43 min
Jul 26, 2:00 PM MDTSpecial Weather StatementSLCWashington45 min
Jul 26, 2:07 PM MDTAreal Flood AdvisorySLCWashington53 min
Jul 26, 2:12 PM MDTAreal Flood AdvisorySLCIron2 hr
Jul 26, 2:45 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield4 hr
Jul 26, 2:53 PM MDTFlash Flood Warning Considerable damage threatSLCIron, Washington3 hr
Jul 26, 3:01 PM MDTSevere Thunderstorm WarningSLCBeaver, Iron29 min
Jul 26, 3:07 PM MDTSevere Thunderstorm WarningSLCBeaver, Iron23 min
Jul 26, 3:20 PM MDTSevere Thunderstorm WarningSLCBeaver, Iron2 min
Jul 26, 3:26 PM MDTSpecial Weather StatementSLCWashington49 min
Jul 26, 3:30 PM MDTSevere Thunderstorm WarningSLCWashington30 min
Jul 26, 3:32 PM MDTAreal Flood AdvisorySLCWashington118 min
Jul 26, 3:32 PM MDTFlash Flood Warning Considerable damage threatSLCBeaver3 hr
Jul 26, 4:00 PM MDTSevere Thunderstorm WarningSLCWashington30 min
Jul 26, 4:34 PM MDTSpecial Weather StatementSLCWashington41 min
Jul 26, 4:55 PM MDTSpecial Weather StatementSLCBeaver50 min
Jul 26, 5:30 PM MDTFlash Flood Warning Considerable damage threatSLCKane6 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.