Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 67, NWS Salt Lake City, UT

September 11, 2012Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 11, 2012, 4:20 PM MDT for Wayne 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 11, 2012, 4:20 PM MDT (22:20 UTC)
Expired
Sep 11, 2012, 7:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Wayne County, UT

The radar

The Cedar City radar (KICX), 164 km from the middle of the area, began a volume at 22:20 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

Grand Junction, CO (KGJT), launched 12:00Z, 10.3 hours before the alert went out and 254 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, Grand Junction, CO at 12:00Z on 2012-09-11Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2012-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 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
2362 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
76 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.

284 
WGUS55 KSLC 112220
FFWSLC
UTC055-120115-
/O.NEW.KSLC.FF.W.0067.120911T2220Z-120912T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
420 PM MDT TUE SEP 11 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WESTERN WAYNE COUNTY IN UTAH

* UNTIL 715 PM MDT

* AT 412 PM MDT...CAPITOL REEF NATIONAL PARK OFFICIALS REPORTED 
FLASH FLOODING ON SULPHUR CREEK IN THE PARK. THIS FLOODING IS FROM 
HEAVY RAINFALL IN THE HEADWATERS OF SULPHUR CREEK EARLIER IN THE 
AFTERNOON AND WILL CONTINUE INTO EARLY THIS EVENING BEFORE 
DIMINISHING. 

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. MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. FLOOD WATERS ARE 
USUALLY DEEPER THAN THEY APPEAR. WHEN ENCOUNTERING FLOODED ROADS 
MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. 

&&

LAT...LON 3843 11144 3842 11111 3833 11102 3816 11110
      3816 11133

$$

PW
1 follow-up statement
371 
WGUS75 KSLC 120113
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
713 PM MDT TUE SEP 11 2012

UTC055-120123-
/O.EXP.KSLC.FF.W.0067.000000T0000Z-120912T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WAYNE UT-
713 PM MDT TUE SEP 11 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 715 PM MDT FOR WESTERN
WAYNE COUNTY...

RUNOFF FROM EARLIER PRECIPITATION HAS DIMINISHED GREATLY AND RIVER 
AND STREAM LEVELS HAVE DECREASED. THEREFORE... THE FLASH FLOOD 
WARNING WILL BE 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 3843 11144 3842 11111 3833 11102 3816 11110
      3816 11133

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 10, 6:08 PM MDTSpecial Weather StatementSLCTooele22 min
Sep 11, 10:52 AM MDTAreal Flood WarningSLCWashington8 hr
Sep 11, 12:20 PM MDTAreal Flood WarningSLCKane4 hr
Sep 11, 12:27 PM MDTFlash Flood WarningSLCWayne4 hr
Sep 11, 1:45 PM MDTFlash Flood WarningSLCWashington3 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.