Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 11, NWS Salt Lake City, UT

July 14, 2021Kane County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 14, 2021, 7:07 PM MDT for Kane 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 14, 2021, 7:07 PM MDT (01:07 UTC)
Expired
Jul 14, 2021, 10:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Kane County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 35 km from the middle of the area, began a volume at 01:06 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

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 1.1 hours before the alert went out and 250 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, Flgstf/Belemont, AZ at 00:00Z on 2021-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 22 joules per kilogram.LCLLFCEL10008507005003002001001 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, Flgstf/Belemont, AZ at 00:00Z on 2021-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -21 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
22 J/kg
Mixed-layer CIN
-222 J/kg
Mixed-layer LCL
1650 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-21 m²/s²
0-3 km storm-relative helicity
2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

266 
WGUS55 KSLC 150107
FFWSLC
UTC025-053-150415-
/O.NEW.KSLC.FF.W.0011.210715T0107Z-210715T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
707 PM MDT Wed Jul 14 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  West Central Kane County in southern Utah...
  East Central Washington County in southwestern Utah...

* Until 1015 PM MDT.

* At 707 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain in Zion National Park. Between 0.5 and 1 inch of rain 
  has fallen. Additional rainfall amounts of 0.5 to 1 inch are 
  possible in 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...
  Zion National Park, Springdale and Rockville.

This includes the following streams and drainages...
  North Fork Virgin River and Orderville Canyon including the 
  Narrows, Mystery Canyon, and Imlay Canyon.

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 3737 11298 3737 11290 3727 11290 3726 11287
      3716 11286 3716 11302 3728 11297

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

$$

LC
2 follow-up statements
277 
WGUS75 KSLC 150255
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
855 PM MDT Wed Jul 14 2021

UTC025-053-150415-
/O.CON.KSLC.FF.W.0011.000000T0000Z-210715T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-Washington UT-
855 PM MDT Wed Jul 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM MDT THIS 
EVENING FOR WEST CENTRAL KANE AND EAST CENTRAL WASHINGTON COUNTIES...

At 855 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain in Zion National Park. Between 0.5 and 1 inch of rain has 
fallen. Additional rainfall amounts of 0.25 to 0.5 inches are 
possible in 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...
  Zion National Park, Springdale and Rockville.

This includes the following streams and drainages...
  North Fork Virgin River and Orderville Canyon including the 
  Narrows, Mystery Canyon, and Imlay Canyon.

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 3737 11298 3737 11290 3727 11290 3726 11287
      3716 11286 3716 11302 3728 11297

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

$$

LC
211 
WGUS75 KSLC 150413
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
1013 PM MDT Wed Jul 14 2021

UTC025-053-150423-
/O.EXP.KSLC.FF.W.0011.000000T0000Z-210715T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-Washington UT-
1013 PM MDT Wed Jul 14 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1015 PM MDT THIS EVENING FOR 
WEST CENTRAL KANE AND EAST CENTRAL WASHINGTON COUNTIES...

Heavy rain has ended in Zion National Park. Flooding is no longer 
expected to pose a threat. However, runoff from earlier heavy rain 
will gradually decrease as light rain diminishes later this evening. 
Please continue to heed any road closures.

LAT...LON 3737 11298 3737 11290 3727 11290 3726 11287
      3716 11286 3716 11302 3728 11297

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 6:20 PM MDTSpecial Weather StatementSLCEmery40 min
Jul 14, 6:25 PM MDTSevere Thunderstorm WarningSLCIron, Washington50 min
Jul 14, 6:49 PM MDTSpecial Weather StatementSLCIron41 min
Jul 14, 7:53 PM MDTSevere Thunderstorm WarningSLCWashington69 min
Jul 15, 2:53 AM MDTFlash Flood WatchSLCBeaver, Emery, Garfield, Iron, Kane, Piute and 4 more25 hr
Jul 15, 4:43 PM MDTSpecial Weather StatementSLCCarbon47 min
Jul 15, 5:01 PM MDTSpecial Weather StatementSLCGarfield44 min
Jul 15, 5:03 PM MDTSpecial Weather StatementSLCTooele57 min
Jul 15, 5:29 PM MDTSpecial Weather StatementSLCWeber61 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.