Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 24, NWS Salt Lake City, UT

July 24, 2012Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 24, 2012, 2:44 PM MDT for Washington County, Utah. It was in force for 6 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 24, 2012, 2:44 PM MDT (20:44 UTC)
Expired
Jul 24, 2012, 8:45 PM MDT
In force
6 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), 82 km from the middle of the area, began a volume at 20:46 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, 8.7 hours before the alert went out and 198 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 2012-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 2012-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2422 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
13 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.

969 
WGUS55 KSLC 242044
FFWSLC
UTC053-250245-
/O.NEW.KSLC.FF.W.0024.120724T2044Z-120725T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
244 PM MDT TUE JUL 24 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 845 PM MDT

* AT 242 PM MDT...HEAVY RAINFALL HAS CONTINUED OVER THE FORT PEARCE 
WASH DRAINAGE BASIN OVER THE PAST SEVERAL HOURS.

* FLASH FLOODING REMAINS LIKELY ALONG THE FORT PEARCE WASH IN SOUTH 
CENTRAL WASHINGTON COUNTY. THE FORT PEARCE GAGE SOUTH OF ST GEORGE 
IS CURRENTLY MEASURING FLOW AT AROUND 633 CUBIC FEET PER SECOND OR 
CFS. FLOW HAS INCREASED OVER THE PAST HOUR AND THIS IS EXPECTED TO 
CONTINUE OVER THE NEXT SEVERAL HOURS.

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 11359 3708 11354 3703 11349 3701 11331
      3699 11332 3699 11353

$$

KRUSE
1 follow-up statement
376 
WGUS75 KSLC 250238
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
838 PM MDT TUE JUL 24 2012

UTC053-250246-
/O.EXP.KSLC.FF.W.0024.000000T0000Z-120725T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
838 PM MDT TUE JUL 24 2012

...THE FLASH FLOOD WARNING FOR THE FORT PEARCE WASH IN SOUTH CENTRAL 
WASHINGTON COUNTY WILL EXPIRE AT 845 PM MDT...

RIVER GAUGES ON THE FORT PEARCE WASH INDICATE WATER LEVELS HAVE 
RECEDED...THUS THE FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE. 

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 11359 3708 11354 3703 11349 3701 11331
      3699 11332 3699 11353

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 8:58 AM MDTFlash Flood WarningSLCWashington6 hr
Jul 24, 12:56 PM MDTFlash Flood WarningSLCGarfield3 hr
Jul 24, 1:28 PM MDTFlash Flood WarningSLCWayne4 hr
Jul 24, 1:34 PM MDTSpecial Weather StatementSLCWashington41 min
Jul 24, 1:45 PM MDTSevere Thunderstorm WarningSLCWashington18 min
Jul 24, 3:18 PM MDTSpecial Weather StatementSLCIron42 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.