Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 52, NWS Salt Lake City, UT

August 19, 2012Kane County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 19, 2012, 4:59 PM MDT for Kane County, Washington County, Utah. It was in force for 4 hr. 2 reports 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
Aug 19, 2012, 4:59 PM MDT (22:59 UTC)
Expired
Aug 19, 2012, 9:00 PM MDT
In force
4 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Kane County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 38 km from the middle of the area, began a volume at 23:01 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
Aug 19, 6:00 PM MDTFLASH FLOODZion Np, UTSIGNIFICANT FLASH FLOODING IN KEYHOLE AND PINE CREEK CANYONS.
Aug 19, 6:20 PM MDTFLASH FLOODZion Np, UTSIGNIFICANT FLASH FLOODING ALONG NORTH CREEK INCLUDING THE SUBWAY. FLASH FLOODING ALSO REPORTED IN SPRY CANYON AND ALONG THE NORTH FORK OF THE VIRGIN.

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, 11.0 hours before the alert went out and 248 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 12:00Z on 2012-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 155 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 12:00Z on 2012-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 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
155 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
1712 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
-32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

250 
WGUS55 KSLC 192259
FFWSLC
UTC025-053-200300-
/O.NEW.KSLC.FF.W.0052.120819T2259Z-120820T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
459 PM MDT SUN AUG 19 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL KANE COUNTY IN UTAH
  EAST CENTRAL WASHINGTON COUNTY IN UTAH...INCLUDING MUCH OF
  ZION NATIONAL PARK 

* UNTIL 900 PM MDT

* AT 448 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS PRODUCING VERY HEAVY RAINFALL ACROSS ZION CANYON 
  INCLUDING THE NARROWS. ADDITIONAL THUNDERSTORMS WERE DEVELOPING 
  ACROSS SOUTHWESTERN PORTIONS OF THE PARK...AS WELL AS EASTWARD 
  ALONG HIGHWAY 9 EAST OF THE EAST ENTRANCE. THIS HEAVY RAINFALL 
  WILL LIKELY CONTINUE THROUGH AT LEAST 6 PM. 

* AREAS WITHIN THE WARNING INCLUDE THE NARROWS...PINE CREEK...SPRY 
  CANYON...ZION CANYON...AND OTHER DRAINAGES ACROSS AND EAST OF 
  ZION NATIONAL PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 3725 11312 3725 11300 3737 11298 3737 11267
      3713 11270 3716 11309

$$

MPS
2 follow-up statements
754 
WGUS75 KSLC 200015
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
615 PM MDT SUN AUG 19 2012

UTC025-053-200300-
/O.CON.KSLC.FF.W.0052.000000T0000Z-120820T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
615 PM MDT SUN AUG 19 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 900 PM MDT FOR WEST 
CENTRAL KANE AND EAST CENTRAL WASHINGTON COUNTIES...INCLUDING MUCH 
OF ZION NATIONAL PARK...

AT 610 PM MDT...RANGERS AT ZION NATIONAL PARK REPORTED SIGNIFICANT 
FLASH FLOODING IN KEYHOLE AND PINE CREEK CANYONS. THIS FLASH 
FLOODING IS RESULTING FROM TORRENTIAL RAINFALL WHICH HAS FALLEN 
ACROSS THE PARK...WITH RADAR ESTIMATES IN EXCESS OF 1 INCH ACROSS 
ZION CANYON SINCE 430 PM. 

FLASH FLOODING WILL CONTINUE THROUGH KEYHOLE AND PINE CREEK 
CANYONS...AS WELL AS OTHER CANYONS ACROSS CENTRAL PORTIONS OF THE 
PARK. SIGNIFICANT FLASH FLOODING IS ALSO LIKELY OCCURRING ALONG 
NORTH CREEK INCLUDING THE SUBWAY AT THIS TIME. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 3725 11312 3725 11300 3737 11298 3737 11267
      3713 11270 3716 11309

$$

MPS
932 
WGUS75 KSLC 200255
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
855 PM MDT SUN AUG 19 2012

UTC025-053-200303-
/O.EXP.KSLC.FF.W.0052.000000T0000Z-120820T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
855 PM MDT SUN AUG 19 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 900 PM MDT FOR WEST CENTRAL
KANE AND EAST CENTRAL WASHINGTON COUNTIES...

RUNOFF FROM EARLIER PRECIPITATION HAS DIMINISHED AND RIVER AND 
STREAM LEVELS HAVE DECREASED. FLOWS ON THE NORTH FORK OF THE VIRGIN 
RIVER IN ZION NATIONAL PARK PEAKED AT OVER 1000 CFS BUT HAVE BEEN 
FALLING FOR THE PAST 2 HOURS. THEREFORE... THE FLASH FLOOD WARNING 
HAS BEEN ALLOWED TO EXPIRE. MONITOR NOAA WEATHER RADIO OR LOCAL 
TELEVISION OR RADIO FOR THE LATEST WEATHER INFORMATION.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

LAT...LON 3725 11312 3725 11300 3737 11298 3737 11267
      3713 11270 3716 11309

$$

DUNN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 2:53 AM MDTFlash Flood WatchSLC19 hr
Aug 19, 2:41 PM MDTFlash Flood WarningSLCKane9 hr
Aug 19, 3:52 PM MDTFlash Flood WarningSLCKane4 hr
Aug 19, 4:29 PM MDTFlash Flood WarningSLCWashington3 hr
Aug 19, 4:39 PM MDTFlash Flood WarningSLCGarfield3 hr
Aug 19, 5:38 PM MDTFlash Flood WarningSLCWashington4 hr

Nearby

Flash Flood Warnings in Utah, 2012Every flash flood warning in 2012

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.