Alert archive / Utah / Flash Flood Warnings in 2011

Flash Flood Warning 4, NWS Salt Lake City, UT

July 8, 2011Garfield County, Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 8, 2011, 3:41 PM MDT for Garfield County, Kane 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 8, 2011, 3:41 PM MDT (21:41 UTC)
Expired
Jul 8, 2011, 6:45 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Garfield County, UT, Kane County, UT

The radar

The Cedar City radar (KICX), 104 km from the middle of the area, began a volume at 21:42 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, 9.7 hours before the alert went out and 222 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, Flgstf/Belemont, AZ at 12:00Z on 2011-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 423 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2011-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
423 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
1308 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
77 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.

553 
WGUS55 KSLC 082141
FFWSLC
UTC017-025-090045-
/O.NEW.KSLC.FF.W.0004.110708T2141Z-110709T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
341 PM MDT FRI JUL 8 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL GARFIELD COUNTY IN UTAH...
  CENTRAL KANE COUNTY IN UTAH...

* UNTIL 645 PM MDT

* AT 330 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  RAINFALL AMOUNTS OF 1.5 INCHES IN A SHORT PERIOD OF TIME OVER      
  WAHWEEP DRAINAGE.  AS SUCH...FLASH FLOODING IS VERY LIKELY IN 
THIS    WASH THROUGH THE EVENING HOURS. THIS AREA FLOWS PAST BIG 
WATER   UTAH AND THEN TERMINATES INTO LAKE POWELL.

* THE STORM PRODUCING FLASH FLOODING WILL OTHERWISE REMAIN OVER
  MAINLY RURAL AREAS OF THE INDICATED COUNTIES.

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 3715 11187 3730 11191 3744 11188 3761 11179
      3736 11167 3711 11159 3704 11160 3703 11172
      3707 11182

$$

MCINERNEY
2 follow-up statements
164 
WGUS75 KSLC 082259
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
459 PM MDT FRI JUL 8 2011

UTC017-025-090045-
/O.CON.KSLC.FF.W.0004.000000T0000Z-110709T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-GARFIELD UT-
459 PM MDT FRI JUL 8 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MDT FOR THE  
   WAHWEEP DRAINAGE AS IT FLOWS INTO LAKE POWELL...

AT 437 PM MDT...REPORTS FROM THE GSENM VISITOR CENTER IN BIG WATER 
UTAH INDICATED EXTENSIVE FLASH FLOODING IN THE WAHWEEP DRAINAGE.  

THUNDERSTORMS OVER THE LOWER WAHWEEP WATERSHED PRODUCED RAINFALL 
AMOUNTS OF 1.5 INCHES IN A SHORT PERIOD OF TIME.  THE RAINFALL 
OCCURRED AROUND 3PM AND HAS SINCE MOVED ON.  IT IS ANTICIPATED THAT 
THE FLOODING...WHILE QUITE LARGE...WILL DECLINE THROUGH THE EVENING 
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.

&&

LAT...LON 3715 11187 3730 11191 3744 11188 3761 11179
      3736 11167 3711 11159 3704 11160 3703 11172
      3707 11182

$$

MCINERNEY
443 
WGUS75 KSLC 090042
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
642 PM MDT FRI JUL 8 2011

UTC017-025-090046-
/O.EXP.KSLC.FF.W.0004.000000T0000Z-110709T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-GARFIELD UT-
642 PM MDT FRI JUL 8 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 645 PM MDT FOR SOUTH
CENTRAL GARFIELD AND CENTRAL KANE COUNTIES...

HEAVY PRECIPITATION HAS DECREASED ALONG WAHWEAP CREEK THIS EVENING. 
RUNOFF FROM EARLIER PRECIPITATION HAS DIMINISHED...AND RIVER AND 
STREAM LEVELS WILL CONTINUE TO LOWER. THEREFORE...THE FLASH FLOOD 
WARNING HAS BEEN ALLOWED TO EXPIRE. 


LAT...LON 3715 11187 3730 11191 3744 11188 3761 11179
      3736 11167 3711 11159 3704 11160 3703 11172
      3707 11182

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 6:20 PM MDTSpecial Weather StatementSLCWasatch40 min
Jul 7, 6:25 PM MDTSpecial Weather StatementSLCTooele65 min
Jul 7, 6:49 PM MDTSevere Thunderstorm WarningSLCBox Elder, Juab, Tooele41 min
Jul 7, 7:31 PM MDTSevere Thunderstorm WarningSLCBox Elder, Juab, Tooele29 min
Jul 8, 4:54 PM MDTSpecial Weather StatementSLCCache51 min

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.