Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 40, NWS Salt Lake City, UT

August 1, 2012Kane County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 1, 2012, 5:23 PM MDT for Kane County, Washington 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 1, 2012, 5:23 PM MDT (23:23 UTC)
Expired
Aug 1, 2012, 9:15 PM MDT
In force
4 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Kane County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 38 km from the middle of the area, began a volume at 23:25 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, 11.4 hours before the alert went out and 246 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 2012-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 259 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 2012-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
259 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
863 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
55 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.

438 
WGUS55 KSLC 012323
FFWSLC
UTC025-053-020315-
/O.NEW.KSLC.FF.W.0040.120801T2323Z-120802T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
523 PM MDT WED AUG 1 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

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

* UNTIL 915 PM MDT

* AT 512 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
HEAVY RAIN FROM A THUNDERSTORM OVER THE SOUTHEASTERN SECTION OF ZION 
NATIONAL PARK.  THIS AREA IS VERY FLASH FLOOD PRONE AND HAS RECEIVED 
RAINFALL AMOUNTS OF 1.30 INCHES IN THE PAST SEVERAL HOURS.  

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ZION
  NATIONAL PARK

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 3729 11298 3735 11292 3734 11284 3733 11281
      3732 11280 3723 11280 3721 11281 3715 11284
      3715 11297 3716 11306 3717 11308

$$

MCINERNEY
2 follow-up statements
224 
WGUS75 KSLC 020115
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
715 PM MDT WED AUG 1 2012

UTC025-053-020315-
/O.CON.KSLC.FF.W.0040.000000T0000Z-120802T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
715 PM MDT WED AUG 1 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT FOR WEST
CENTRAL KANE AND EAST CENTRAL WASHINGTON COUNTIES...

AT 707 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE FLASH FLOODING OVER AND ADJACENT TO EASTERN PORTIONS OF 
ZION NATIONAL PARK. RAINFALL FROM EARLIER THUNDERSTORMS WILL 
CONTINUE TO CHANNEL THROUGH NARROW SLOT CANYONS AND INTO LARGER 
RIVER STEMS THROUGH 915 PM MDT.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ZION NATIONAL
PARK

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 3729 11298 3735 11292 3734 11284 3733 11281
      3732 11280 3723 11280 3721 11281 3715 11284
      3715 11297 3716 11306 3717 11308

$$

MERRILL
814 
WGUS75 KSLC 020314
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
914 PM MDT WED AUG 1 2012

UTC025-053-020321-
/O.EXP.KSLC.FF.W.0040.000000T0000Z-120802T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
914 PM MDT WED AUG 1 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 915 PM MDT FOR WEST CENTRAL
KANE AND EAST CENTRAL WASHINGTON COUNTIES...

PRECIPITATION HAS TAPERED OFF OVER THE EASTERN PORTIONS OF ZION 
NATIONAL PARK. THEREFORE...THE FLASH FLOOD WARNING HAS BEEN ALLOWED 
TO EXPIRE. ALTHOUGH WATER LEVELS MAY REMAIN HIGH IN SOME AREAS IN 
THE EASTERN PORTIONS OF ZION NATIONAL PARK...THEY WILL GRADUALLY 
RECEDE THROUGH THE REST OF THIS EVENING. MONITOR NOAA WEATHER RADIO 
OR LOCAL TELEVISION OR RADIO FOR THE LATEST WEATHER INFORMATION.

LAT...LON 3729 11298 3735 11292 3734 11284 3733 11281
      3732 11280 3723 11280 3721 11281 3715 11284
      3715 11297 3716 11306 3717 11308

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 6:30 PM MDTFlash Flood WarningSLCIron4 hr
Jul 31, 6:30 PM MDTSpecial Weather StatementSLCKane30 min
Jul 31, 10:51 PM MDTFlash Flood WarningSLCWashington4 hr
Aug 1, 2:30 AM MDTFlash Flood WatchSLC20 hr
Aug 1, 2:51 PM MDTFlash Flood WarningSLCGarfield4 hr
Aug 1, 3:09 PM MDTFlash Flood WarningSLCGarfield, Kane6 hr
Aug 1, 4:05 PM MDTFlash Flood WarningSLCKane4 hr
Aug 1, 5:17 PM MDTFlash Flood WarningSLCWashington4 hr
Aug 1, 5:27 PM MDTFlash Flood WarningSLCCarbon, Emery4 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.