Alert archive / Utah / Flash Flood Warnings in 2011

Flash Flood Warning 50, NWS Salt Lake City, UT

September 13, 2011Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 13, 2011, 5:44 PM MDT for 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
Sep 13, 2011, 5:44 PM MDT (23:44 UTC)
Expired
Sep 13, 2011, 8:45 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Washington County, UT

The radar

The Cedar City radar (KICX), 44 km from the middle of the area, began a volume at 23:48 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, 11.7 hours before the alert went out and 241 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, Las Vegas, NV at 12:00Z on 2011-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 239 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2011-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 square meters per square second.1939Sfc1 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
239 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
1707 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

528 
WGUS55 KSLC 132344
FFWSLC
UTC053-140245-
/O.NEW.KSLC.FF.W.0050.110913T2344Z-110914T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
544 PM MDT TUE SEP 13 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

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

* UNTIL 845 PM MDT

* AT 534 PM MDT...PARK RANGERS REPORTED FLASH FLOODING ALONG PINE 
CREEK AND CLEAR CREEK WITH WATER 7 TO 8 FEET DEEP. THIS DRAINAGE 
RUNS ALONG THE ROAD FROM THE EAST ENTRANCE OF THE PARK TOWARDS THE 
VISITORS CENTER. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ZION   
NATIONAL PARK AND SPRINGVILLE.

HEAVY RAINS WILL CONTINUE ACROSS THIS AREA THROUGH AT LEAST 600 PM 
AND ADDITIONAL FLASH FLOODING IS LIKELY. 

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. MOVE TO HIGHER GROUND.

&&

LAT...LON 3731 11315 3731 11290 3712 11291 3709 11315

$$

PW
2 follow-up statements
488 
WGUS75 KSLC 140127
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
727 PM MDT TUE SEP 13 2011

UTC053-140245-
/O.CON.KSLC.FF.W.0050.000000T0000Z-110914T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
727 PM MDT TUE SEP 13 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM MDT FOR EAST
CENTRAL WASHINGTON COUNTY...

AT 717 PM MDT...

HEAVY RAINS HAVE ENDING IN THE WARNING AREA AND THE THREAT OF 
ADDITIONAL HEAVY RAIN HAS DIMINISHED. HOWEVER...FLOODING IS STILL 
LIKELY OCCURRING ALONG STREAMS IN THE PINE CREEK DRAINAGE AS WELL AS 
ALONG THE NORTH FORK OF THE VIRGIN RIVER THROUGH THE LOWER PORTIONS 
OF ZION NATIONAL PARK. WATER LEVELS ARE EXPECTED TO FALL OVER THE 
NEXT HOUR OR TWO. 
 
LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 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 3731 11315 3731 11290 3712 11291 3709 11315

$$

PW
927 
WGUS75 KSLC 140242
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
842 PM MDT TUE SEP 13 2011

UTC053-140248-
/O.EXP.KSLC.FF.W.0050.000000T0000Z-110914T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
842 PM MDT TUE SEP 13 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 845 PM MDT FOR EAST CENTRAL
WASHINGTON COUNTY...

RUNOFF FROM EARLIER PRECIPITATION HAS DIMINISHED GREATLY AND RIVER
AND STREAM LEVELS HAVE DECREASED. REPORTS INDICATE THAT FLOODING HAS
ENDED. THEREFORE... THE FLASH FLOOD WARNING HAS BEEN ALLOWED TO
EXPIRE. 

SOME ADDITIONAL RAINFALL IS EXPECTED IN THIS AREA OVERNIGHT BUT THE 
THREAT OF RENEWED FLASH FLOODING FROM THIS IS VERY LOW. 

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 3731 11315 3731 11290 3712 11291 3709 11315

$$

PW

Nearby

Flash Flood Warnings in Utah, 2011Every flash flood warning in 2011

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.