Alert archive / Utah / Flash Flood Warnings in 2011

Flash Flood Warning 20, NWS Salt Lake City, UT

July 31, 2011Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 31, 2011, 6:21 PM MDT for 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 31, 2011, 6:21 PM MDT (00:21 UTC)
Expired
Jul 31, 2011, 9:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Kane County, UT

The radar

The Cedar City radar (KICX), 135 km from the middle of the area, began a volume at 00:21 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 00:00Z, 0.4 hours before the alert went out and 238 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 00:00Z on 2011-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2011-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
2268 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
-18 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.

234 
WGUS55 KSLC 010021
FFWSLC
UTC025-010315-
/O.NEW.KSLC.FF.W.0020.110801T0021Z-110801T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
621 PM MDT SUN JUL 31 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL KANE COUNTY IN UTAH...

* UNTIL 915 PM MDT

* AT 616 PM MDT...HEAVY RAINFALL HAS FALLEN OVER THE CROTON CANYON 
DRAINAGE IN EAST CENTRAL KANE COUNTY.

* UP TO 1.5 INCHES OF RAIN HAS FALLEN IN THE PAST HOUR. FLASH 
FLOODING IS EXPECTED IN THE CROTON CANYON DRAINAGE FROM THE 
HEADWATERS TO THE TERMINATION AT LAKE POWELL. 

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 3748 11147 3750 11131 3722 11123 3716 11130
      3722 11138

$$

KRUSE
2 follow-up statements
611 
WGUS75 KSLC 010210
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
810 PM MDT SUN JUL 31 2011

UTC025-010315-
/O.CON.KSLC.FF.W.0020.000000T0000Z-110801T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-
810 PM MDT SUN JUL 31 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT FOR EAST
CENTRAL KANE COUNTY...

AT 759 PM MDT...ALTHOUGH THE THUNDERSTORMS THAT PRODUCED HEAVY 
RAINFALL OVER CROTON CREEK AREA HAVE MOVED AWAY...DRY WASHES AND 
SMALL STREAMS IN THIS AREA ARE LIKELY RUNNING HIGH AN WILL SO FOR 
ANOTHER HOUR OR SO. 

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 3748 11147 3750 11131 3722 11123 3716 11130
      3722 11138

$$

STRUTHWOLF
842 
WGUS75 KSLC 010316
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
916 PM MDT SUN JUL 31 2011

UTC025-010324-
/O.EXP.KSLC.FF.W.0020.000000T0000Z-110801T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-
916 PM MDT SUN JUL 31 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 915 PM MDT FOR EAST CENTRAL
KANE COUNTY...

HEAVY RAIN HAS ENDED OVER THE CROTON CANYON DRAINAGE IN EAST CENTRAL 
KANE COUNTY. RUNOFF FROM THE HEAVY RAIN EARLIER WILL GRADUALLY 
DECREASE THROUGH THE REST OF THE EVENING. 

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 3748 11147 3750 11131 3722 11123 3716 11130
      3722 11138

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 6:59 AM MDTAreal Flood AdvisorySLCBox Elder, Cache, Davis, Weber2 hr
Aug 1, 3:07 PM MDTFlash Flood WarningSLCGarfield, Wayne3 hr
Aug 1, 3:35 PM MDTFlash Flood WarningSLCGarfield, Wayne3 hr
Aug 1, 5:39 PM MDTSevere Thunderstorm WarningSLCBox Elder36 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.