Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 19, NWS Salt Lake City, UT

July 19, 2021Iron County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 19, 2021, 2:34 PM MDT for Iron County, 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 19, 2021, 2:34 PM MDT (20:34 UTC)
Expired: Jul 19, 2021, 5:30 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), 48 km from the middle of the area, began a volume at 20:33 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 19, 4:04 PM MDT	FLASH FLOOD	6 Ne Pinto, UT	SIGNIFICANT WATER RUNNING INTO OLD IRONTOWN, CUT OFF ACCESS TO TOWN ON HWY 56 ALONG MP30.

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 230 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: 127 J/kg
Mixed-layer CIN: -232 J/kg
Mixed-layer LCL: 1964 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

733 
WGUS55 KSLC 192034
FFWSLC
UTC021-053-192330-
/O.NEW.KSLC.FF.W.0019.210719T2034Z-210719T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
234 PM MDT Mon Jul 19 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southwestern Iron County in southern Utah...
  Northeastern Washington County in southwestern Utah...

* Until 530 PM MDT.

* At 234 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.75 and 3 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...
  Little Pinto Creek and portions of West Pinto Road intersecting 
  with Little Pinto Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3754 11344 3756 11344 3760 11346 3761 11345
      3759 11343 3758 11341 3758 11337 3757 11336
      3753 11336 3752 11336 3751 11339 3752 11342

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

$$

SW

2 follow-up statements

104 
WGUS75 KSLC 192209
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
409 PM MDT Mon Jul 19 2021

UTC021-053-192330-
/O.CON.KSLC.FF.W.0019.000000T0000Z-210719T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-Washington UT-
409 PM MDT Mon Jul 19 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MDT THIS 
AFTERNOON FOR SOUTHWESTERN IRON AND NORTHEASTERN WASHINGTON 
COUNTIES...

At 409 PM MDT, local law enforcement reported flash flooding in Old 
Irontown. Between 3 and 5 inches of rain have fallen. Flash flooding 
is already occurring.

HAZARD...Life threatening flash flooding. Heavy rain producing
         flash flooding.

SOURCE...Law enforcement reported.

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

Some locations that will experience flash flooding include...
  Little Pinto Creek through Old Irontown

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3754 11344 3756 11344 3760 11346 3761 11345
      3759 11343 3758 11341 3758 11337 3757 11336
      3753 11336 3752 11336 3751 11339 3752 11342

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

$$

SW

755 
WGUS75 KSLC 192333
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
533 PM MDT Mon Jul 19 2021

UTC021-053-192343-
/O.EXP.KSLC.FF.W.0019.000000T0000Z-210719T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-Washington UT-
533 PM MDT Mon Jul 19 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTHWESTERN IRON AND 
NORTHEASTERN WASHINGTON COUNTIES...

The heavy rain has moved out of the warned area. Runoff from earlier 
rainfall and flash flooding will continue to decrease through the 
evening. Additional flooding is no longer expected to pose a threat. 
Please continue to heed remaining road closures.

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

LAT...LON 3754 11344 3756 11344 3760 11346 3761 11345
      3759 11343 3758 11341 3758 11337 3757 11336
      3753 11336 3752 11336 3751 11339 3752 11342

$$

SW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 7:02 PM MDT	Special Weather Statement	SLC	Tooele	43 min
Jul 18, 7:54 PM MDT	Special Weather Statement	SLC	Tooele	51 min
Jul 19, 4:32 AM MDT	Flash Flood Watch	SLC	Beaver, Carbon, Duchesne, Emery, Garfield, Iron and 12 more	19 hr
Jul 19, 1:44 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane, Washington	5 hr
Jul 19, 2:45 PM MDT	Areal Flood Advisory	SLC	Iron	3 hr
Jul 19, 2:53 PM MDT	Special Weather Statement	SLC	Iron	52 min
Jul 19, 3:04 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Iron	3 hr
Jul 19, 3:22 PM MDT	Severe Thunderstorm Warning	SLC	Iron	38 min
Jul 19, 3:46 PM MDT	Special Weather Statement	SLC	Utah	44 min
Jul 19, 4:54 PM MDT	Special Weather Statement	SLC	Davis, Salt Lake	36 min
Jul 19, 5:57 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Iron, 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.