Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 40, NWS Salt Lake City, UT

July 24, 2021Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 24, 2021, 2:13 PM MDT for Washington 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: Jul 24, 2021, 2:13 PM MDT (20:13 UTC)
Expired: Jul 24, 2021, 5:15 PM MDT
In force: 3 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Washington County, UT

The radar

The Cedar City radar (KICX), 64 km from the middle of the area, began a volume at 20:14 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

Time	Report	Where	Remark
Jul 24, 2:45 PM MDT	FLASH FLOOD	Hildale, UT	VIDEO SHOWS KNEE DEEP WATER FLOWING DOWN A STREET IN HILDALE, ERODING A PORTION OF THE ROAD. VIDEO RECEIVED VIA SOCIAL MEDIA. EXACT LOCATION UNKNOWN.

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, 8.2 hours before the alert went out and 226 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1053 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: -9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

920 
WGUS55 KSLC 242013
FFWSLC
UTC053-242315-
/O.NEW.KSLC.FF.W.0040.210724T2013Z-210724T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
213 PM MDT Sat Jul 24 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southeastern Washington County in southwestern Utah...

* Until 515 PM MDT.

* At 213 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 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...
  Short Creek draining through Hildale.

This includes the following streams and drainages...
  Second Creek, Short Creek, South Creek, and Water Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3700 11310 3709 11294 3707 11290 3705 11290
      3700 11293 3700 11299 3700 11300

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

$$

SW

2 follow-up statements

503 
WGUS75 KSLC 242202
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
402 PM MDT Sat Jul 24 2021

UTC053-242315-
/O.CON.KSLC.FF.W.0040.000000T0000Z-210724T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
402 PM MDT Sat Jul 24 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM MDT THIS 
AFTERNOON FOR SOUTHEASTERN WASHINGTON COUNTY...

At 402 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the Short Creek watershed. Between 0.5 and 1 inch of 
rain has fallen 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 creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Short Creek draining through Hildale.

This includes the following streams and drainages...
  Second Creek, Short Creek, South Creek, and Water Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3700 11310 3709 11294 3707 11290 3705 11290
      3700 11293 3700 11299 3700 11300

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

$$

SW

138 
WGUS75 KSLC 242316
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
516 PM MDT Sat Jul 24 2021

UTC053-242326-
/O.EXP.KSLC.FF.W.0040.000000T0000Z-210724T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
516 PM MDT Sat Jul 24 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTHEASTERN WASHINGTON 
COUNTY...

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

LAT...LON 3700 11310 3709 11294 3707 11290 3705 11290
      3700 11293 3700 11299 3700 11300

$$

SW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 6:14 PM MDT	Areal Flood Advisory	SLC	Washington	61 min
Jul 24, 3:23 AM MDT	Flash Flood Watch	SLC	Beaver, Garfield, Iron, Kane, Piute, Washington and 1 more	42 hr
Jul 24, 12:56 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	3 hr
Jul 24, 12:58 PM MDT	Special Weather Statement	SLC	Kane	32 min
Jul 24, 1:34 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield, Kane	4 hr
Jul 24, 2:24 PM MDT	Severe Thunderstorm Warning	SLC	Washington	21 min
Jul 24, 3:16 PM MDT	Severe Thunderstorm Warning	SLC	Washington	29 min
Jul 24, 3:40 PM MDT	Severe Thunderstorm Warning	SLC	Iron, Washington	35 min
Jul 24, 4:04 PM MDT	Severe Thunderstorm Warning	SLC	Washington	26 min
Jul 24, 4:07 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane, Washington	3 hr
Jul 24, 4:12 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Iron, Washington	3 hr
Jul 24, 4:30 PM MDT	Severe Thunderstorm Warning	SLC	Washington	30 min
Jul 24, 5:24 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Washington	3 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.