Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 11, NWS Salt Lake City, UT

July 16, 2012Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 16, 2012, 1:13 PM MDT for Washington County, Utah. It was in force for 11 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 16, 2012, 1:13 PM MDT (19:13 UTC)
Expired
Jul 17, 2012, 12:26 AM MDT
In force
11 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), 77 km from the middle of the area, began a volume at 19:14 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.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 7.2 hours before the alert went out and 206 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 2012-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 610 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 2012-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
610 J/kg
Mixed-layer CIN
-168 J/kg
Mixed-layer LCL
1601 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

657 
WGUS55 KSLC 161913
FFWSLC
UTC053-170115-
/O.NEW.KSLC.FF.W.0011.120716T1913Z-120717T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
113 PM MDT MON JUL 16 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  THE FORT PEARCE WASH IN SOUTH CENTRAL WASHINGTON COUNTY IN UTAH

* UNTIL 715 PM MDT

* AT 106 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  HEAVY RAINFALL ACROSS PORTIONS OF THE FORT PEARCE WASH DRAINAGE 
  AREA. RUNOFF FROM THIS HEAVY RAINFALL IS EXPECTED TO RESULT IN A 
  FLASH FLOOD THROUGH THE FORT PEARCE WASH TO ITS CONFLUENCE WITH 
  THE VIRGIN RIVER NEAR ST GEORGE. 

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 3708 11357 3703 11310 3700 11310 3700 11355

$$

MPS
4 follow-up statements
321 
WGUS75 KSLC 162136
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
336 PM MDT MON JUL 16 2012

UTC053-170115-
/O.CON.KSLC.FF.W.0011.000000T0000Z-120717T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
336 PM MDT MON JUL 16 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM MDT FOR FORT 
PEARCE WASH IN SOUTH CENTRAL WASHINGTON COUNTY...

EXCESSIVE RUNOFF FROM EARLIER HEAVY RAINFALL CONTINUES TO MAKE ITS 
WAY THROUGH FORT PEARCE WASH. THIS WILL CONTINUE THROUGH THE 
REMAINDER OF THE AFTERNOON UNTIL THIS RUNOFF REACHES THE CONFLUENCE 
WITH THE VIRGIN RIVER.


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 3708 11357 3703 11310 3700 11310 3700 11355

$$

MPS
390 
WGUS55 KSLC 170109
FFWSLC
UTC053-170715-
/O.EXT.KSLC.FF.W.0011.000000T0000Z-120717T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
709 PM MDT MON JUL 16 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  THE FORT PEARCE WASH IN SOUTH CENTRAL WASHINGTON COUNTY IN UTAH

* UNTIL 115 AM MDT TUESDAY

* EXCESSIVE RUNOFF FROM EARLIER HEAVY RAINFALL CONTINUES TO WORK ITS 
  WAY THROUGH THE FORT PEARCE WASH...AND WILL CONTINUE TO RESULT IN 
  FLASH FLOODING WITHIN THE WASH THROUGH THE REMAINDER OF THE 
  EVENING. RADAR ESTIMATES INDICATE AS MUCH AS 3 INCHES OF RAIN FELL 
  WITHIN PORTIONS OF THE WASH. 

* FLASH FLOODING CAN BE EXPECTED ALONG THE FORT PEARCE WASH ACROSS 
  WASHINGTON COUNTY TO ITS CONFLUENCE WITH THE VIRGIN RIVER.

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.

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 3708 11357 3703 11310 3700 11310 3700 11355

$$

MPS
069 
WGUS75 KSLC 170203
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
803 PM MDT MON JUL 16 2012

UTC053-170715-
/O.CON.KSLC.FF.W.0011.000000T0000Z-120717T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
803 PM MDT MON JUL 16 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 AM MDT FOR FORT 
PEARCE WASH IN SOUTH CENTRAL WASHINGTON COUNTY...

AT 755 PM MDT...A GAUGE ON THE FORT PEARCE WASH INDICATED A RISE OF 
OVER 8 FEET IN LESS THAN AN HOUR. THIS FLOOD WAVE WILL CONTINUE TO 
MOVE DOWN THE FORT PEARCE WASH TO THE CONFLUENCE WITH THE VIRGIN 
RIVER THROUGH THE REMAINDER OF THE EVENING. 

THIS THUNDERSTORM WITH EXCESSIVE RAIN WILL OTHERWISE REMAIN OVER
MAINLY RURAL AREAS OF THE INDICATED COUNTY.

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 3708 11357 3703 11310 3700 11310 3700 11355

$$

MPS
153 
WGUS75 KSLC 170626
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1226 AM MDT TUE JUL 17 2012

UTC053-170633-
/O.CAN.KSLC.FF.W.0011.000000T0000Z-120717T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
1226 AM MDT TUE JUL 17 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTH CENTRAL
WASHINGTON COUNTY...

WATER LEVELS IN THE FORT PEARCE WASH IN SOUTHERN WASHINGTON COUNTY 
HAVE FALLEN DOWN TO ONLY A SHALLOW FLOW AS OF MIDNIGHT. THEREFORE... 
THE FLASH FLOOD WARNING HAS BEEN CANCELLED. MONITOR NOAA WEATHER 
RADIO OR LOCAL TELEVISION OR RADIO FOR THE LATEST WEATHER 
INFORMATION.

LAT...LON 3708 11357 3703 11310 3700 11310 3700 11355

$$

PW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 15, 6:20 PM MDTSevere Thunderstorm WarningSLCEmery55 min
Jul 15, 8:06 PM MDTFlash Flood WarningSLCWashington4 hr
Jul 16, 1:04 PM MDTFlash Flood WarningSLCWayne3 hr
Jul 16, 1:24 PM MDTSpecial Weather StatementSLCTooele66 min
Jul 16, 1:37 PM MDTSevere Thunderstorm WarningSLCKane38 min
Jul 16, 1:49 PM MDTFlash Flood WarningSLCKane, Washington4 hr
Jul 16, 2:00 PM MDTSevere Thunderstorm WarningSLCBox Elder, Tooele43 min
Jul 16, 2:20 PM MDTSpecial Weather StatementSLC70 min
Jul 16, 2:26 PM MDTSpecial Weather StatementSLC49 min
Jul 16, 2:33 PM MDTSevere Thunderstorm WarningSLCKane27 min
Jul 16, 2:55 PM MDTFlash Flood WarningSLCKane3 hr
Jul 16, 3:01 PM MDTSpecial Weather StatementSLC44 min
Jul 16, 3:24 PM MDTSpecial Weather StatementSLCCarbon51 min
Jul 16, 4:10 PM MDTSevere Thunderstorm WarningSLCWashington50 min
Jul 16, 4:38 PM MDTSpecial Weather StatementSLCWeber67 min
Jul 16, 4:49 PM MDTSpecial Weather StatementSLC26 min
Jul 16, 4:54 PM MDTFlash Flood WarningSLCUtah50 min
Jul 16, 4:56 PM MDTSevere Thunderstorm WarningSLCWashington49 min
Jul 16, 5:00 PM MDTSpecial Weather StatementSLCRich60 min
Jul 16, 5:01 PM MDTFlash Flood WarningSLCWashington4 hr
Jul 16, 5:10 PM MDTSevere Thunderstorm WarningSLCSalt Lake, Utah50 min
Jul 16, 5:19 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake, Tooele41 min
Jul 16, 5:22 PM MDTSpecial Weather StatementSLCCache38 min
Jul 16, 5:28 PM MDTFlash Flood WarningSLCKane, Washington6 hr
Jul 16, 5:54 PM MDTSpecial Weather StatementSLCDavis, Salt Lake51 min

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