Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 53, NWS Salt Lake City, UT

July 26, 2021Iron County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 26, 2021, 2:53 PM MDT for Iron County, Washington 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 26, 2021, 2:53 PM MDT (20:53 UTC)
Expired: Jul 26, 2021, 6:00 PM MDT
In force: 3 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Iron County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 58 km from the middle of the area, began a volume at 20:54 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

Las Vegas, NV (KVEF), launched 12:00Z, 8.9 hours before the alert went out and 225 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: 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.

676 
WGUS55 KSLC 262053
FFWSLC
UTC021-053-270000-
/O.NEW.KSLC.FF.W.0053.210726T2053Z-210727T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  South Central Iron County in southern Utah...
  Northern Washington County in southwestern Utah...

* Until 600 PM MDT.

* At 253 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the headwaters of the Pinto Creek watershed. 
  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...
  Pinto and Newcastle.

This includes the following highways...
	Utah Route 56 near mile marker 32.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3764 11353 3766 11354 3768 11355 3768 11354
      3766 11352 3764 11349 3761 11347 3758 11346
      3754 11348 3752 11350 3751 11355 3752 11356
      3753 11356 3756 11357 3759 11355 3762 11352

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

$$

SW

2 follow-up statements

020 
WGUS75 KSLC 262251
FFSSLC

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

UTC021-053-270000-
/O.CON.KSLC.FF.W.0053.000000T0000Z-210727T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-Washington UT-
451 PM MDT Mon Jul 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING 
FOR SOUTH CENTRAL IRON AND NORTHERN WASHINGTON COUNTIES...

At 451 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the headwaters of the Pinto Creek watershed. Between 2 
and 2.5 inches of rain have fallen. Minor flash flooding was 
observed near Newcastle, therefore, the warning will continue.

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...
  Pinto Creek draining through State Route 56 near Newcastle.

This includes the following highways...
	Utah Route 56 near mile marker 32.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3764 11353 3766 11354 3768 11355 3768 11354
      3766 11352 3764 11349 3761 11347 3758 11346
      3754 11348 3752 11350 3751 11355 3752 11356
      3753 11356 3756 11357 3759 11355 3762 11352

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

$$

SW

030 
WGUS75 KSLC 270000
FFSSLC

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

UTC021-053-270010-
/O.EXP.KSLC.FF.W.0053.000000T0000Z-210727T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-Washington UT-
600 PM MDT Mon Jul 26 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTH CENTRAL IRON AND 
NORTHERN WASHINGTON COUNTIES...

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

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

LAT...LON 3764 11353 3766 11354 3768 11355 3768 11354
      3766 11352 3764 11349 3761 11347 3758 11346
      3754 11348 3752 11350 3751 11355 3752 11356
      3753 11356 3756 11357 3759 11355 3762 11352

$$

SW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 6:06 PM MDT	Special Weather Statement	SLC	Washington	39 min
Jul 25, 6:16 PM MDT	Special Weather Statement	SLC	Washington	44 min
Jul 26, 3:37 AM MDT	Flash Flood Watch	SLC	Beaver, Garfield, Iron, Kane, Piute, Washington and 1 more	20 hr
Jul 26, 1:13 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane, Washington	3 hr
Jul 26, 1:37 PM MDT	Severe Thunderstorm Warning	SLC	Washington	23 min
Jul 26, 1:40 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	3 hr
Jul 26, 1:47 PM MDT	Special Weather Statement	SLC	Piute	43 min
Jul 26, 2:00 PM MDT	Special Weather Statement	SLC	Washington	45 min
Jul 26, 2:07 PM MDT	Areal Flood Advisory	SLC	Washington	53 min
Jul 26, 2:12 PM MDT	Areal Flood Advisory	SLC	Iron	2 hr
Jul 26, 2:35 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Iron	115 min
Jul 26, 2:45 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	4 hr
Jul 26, 3:01 PM MDT	Severe Thunderstorm Warning	SLC	Beaver, Iron	29 min
Jul 26, 3:07 PM MDT	Severe Thunderstorm Warning	SLC	Beaver, Iron	23 min
Jul 26, 3:20 PM MDT	Severe Thunderstorm Warning	SLC	Beaver, Iron	2 min
Jul 26, 3:26 PM MDT	Special Weather Statement	SLC	Washington	49 min
Jul 26, 3:30 PM MDT	Severe Thunderstorm Warning	SLC	Washington	30 min
Jul 26, 3:32 PM MDT	Areal Flood Advisory	SLC	Washington	118 min
Jul 26, 3:32 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Beaver	3 hr
Jul 26, 4:00 PM MDT	Severe Thunderstorm Warning	SLC	Washington	30 min
Jul 26, 4:34 PM MDT	Special Weather Statement	SLC	Washington	41 min
Jul 26, 4:55 PM MDT	Special Weather Statement	SLC	Beaver	50 min
Jul 26, 5:30 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	6 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.