Alert archive / Utah / Flash Flood Warnings in 2011

Flash Flood Warning 11, NWS Salt Lake City, UT

July 25, 2011Garfield County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 25, 2011, 3:33 PM MDT for Garfield 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: Jul 25, 2011, 3:33 PM MDT (21:33 UTC)
Expired: Jul 25, 2011, 6:30 PM MDT
In force: 3 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Flood severity: None

County Garfield County, UT

The radar

The Cedar City radar (KICX), 27 km from the middle of the area, began a volume at 21:33 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.6 hours before the alert went out and 274 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 256 J/kg
Mixed-layer CIN: -163 J/kg
Mixed-layer LCL: 1279 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

635 
WGUS55 KSLC 252133
FFWSLC
UTC017-260030-
/O.NEW.KSLC.FF.W.0011.110725T2133Z-110726T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
333 PM MDT MON JUL 25 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN GARFIELD COUNTY IN UTAH...

* UNTIL 630 PM MDT

* AT 324 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAINFALL OVER THE MAMMOTH CREEK...ASAY CREEK...AND WEST 
  FORK CREEK DRAINAGES. ALL OF THESE DRAINAGES WILL CONVERGE ON THE 
  SEVIER RIVER SOUTH OF HATCH. FLASH FLOODING WILL RESULT FROM THESE
  HEAVY RAIN PRODUCING THUNDERSTORMS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HATCH

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.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

&&

LAT...LON 3767 11266 3767 11239 3760 11247 3755 11250
      3755 11267

$$

CONGER

1 follow-up statement

510 
WGUS75 KSLC 252344
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
544 PM MDT MON JUL 25 2011

UTC017-260030-
/O.CON.KSLC.FF.W.0011.000000T0000Z-110726T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GARFIELD UT-
544 PM MDT MON JUL 25 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR
SOUTHWESTERN GARFIELD COUNTY...

AT 542 PM MDT...THE THUNDERSTORMS THAT PRODUCED VERY HEAVY RAIN 
HAVE MOVED AWAY FROM THE WARNED AREA. HEAVY RUNOFF FROM THE EARLIER 
RAINFALL WILL CREATE FLASH FLOODING ALONG MAMMOTH CREEK...ASAY 
CREEK...AND WEST FORK CREEK. THIS HEAVY RUNOFF WILL MOVE IN THE 
SEVIER RIVER SOUTH OF HATCH.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HATCH

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 3767 11266 3767 11239 3760 11247 3755 11250
      3755 11267

$$

CONGER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 2:58 PM MDT	Areal Flood Advisory	SLC	Garfield	3 hr

Nearby

Flash Flood Warnings in Utah, 2011 Every 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.