Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 49, NWS Salt Lake City, UT

August 19, 2012Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 19, 2012, 3:52 PM MDT for Kane County, Utah. It was in force for 4 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
Aug 19, 2012, 3:52 PM MDT (21:52 UTC)
Expired
Aug 19, 2012, 7:45 PM MDT
In force
4 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), 69 km from the middle of the area, began a volume at 21:56 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, 9.9 hours before the alert went out and 217 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 2012-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 155 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 2012-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 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
155 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
1712 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
-32 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.

049 
WGUS55 KSLC 192152
FFWSLC
UTC025-200145-
/O.NEW.KSLC.FF.W.0049.120819T2152Z-120820T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
352 PM MDT SUN AUG 19 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL KANE COUNTY IN UTAH...INCLUDING THE CITY OF 
  KANAB...ALONG WITH KANAB CREEK AND JOHNSON WASH

* UNTIL 745 PM MDT

* AT 347 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  HEAVY RAIN FROM A THUNDERSTORM OVER THE WARNED AREA. RADAR 
  ESTIMATES OF 0.75 TO 1 INCH HAVE FALLEN AROUND KANAB EASTWARD INTO 
  THE JOHNSON WASH.  

* ADDITIONAL HEAVY RAINFALL IS EXPECTED IN AND AROUND KANAB AS WELL 
  AS THE JOHNSON WASH EAST OF KANAB THROUGH 5 PM.

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 3728 11220 3700 11208 3700 11258 3713 11258

$$

MPS
2 follow-up statements
930 
WGUS75 KSLC 192304
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
504 PM MDT SUN AUG 19 2012

UTC025-200145-
/O.CON.KSLC.FF.W.0049.000000T0000Z-120820T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-
504 PM MDT SUN AUG 19 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM MDT FOR SOUTH
CENTRAL KANE COUNTY INCLUDING KANAB...KANAB CREEK AND JOHNSON WASH...

AT 500 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 1 
TO 2 INCHES OF RAIN HAS FALLEN IN AND AROUND THE KANAB AREA SINCE 3 
PM. 

THUNDERSTORMS HAVE GENERALLY WEAKENED ACROSS THE AREA...HOWEVER 
EXCESS RUNOFF FROM THIS HEAVY RAINFALL IS LIKELY STILL MAKING ITS 
WAY THROUGH KANAB CREEK AND JOHNSON WASH...AND WILL CONTINUE TO DO 
SO THROUGH EARLY EVENING.

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 3728 11220 3700 11208 3700 11258 3713 11258

$$

MPS
322 
WGUS75 KSLC 200139
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
739 PM MDT SUN AUG 19 2012

UTC025-200148-
/O.EXP.KSLC.FF.W.0049.000000T0000Z-120820T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-
739 PM MDT SUN AUG 19 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 745 PM MDT FOR AREAS 
AROUND KANAB IN SOUTH CENTRAL KANE COUNTY...

RUNOFF FROM EARLIER PRECIPITATION HAS DIMINISHED GREATLY AND RIVER 
AND STREAM LEVELS HAVE DECREASED. THEREFORE... THE FLASH FLOOD 
WARNING HAS BEEN 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 3728 11220 3700 11208 3700 11258 3713 11258

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 2:53 AM MDTFlash Flood WatchSLC19 hr
Aug 19, 2:41 PM MDTFlash Flood WarningSLCKane9 hr
Aug 19, 4:29 PM MDTFlash Flood WarningSLCWashington3 hr
Aug 19, 4:39 PM MDTFlash Flood WarningSLCGarfield3 hr
Aug 19, 4:59 PM MDTFlash Flood WarningSLCKane, Washington4 hr
Aug 19, 5:38 PM MDTFlash Flood WarningSLCWashington4 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.