Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 51, NWS Salt Lake City, UT

August 19, 2012Garfield County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 19, 2012, 4:39 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
Aug 19, 2012, 4:39 PM MDT (22:39 UTC)
Expired
Aug 19, 2012, 7:30 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), 139 km from the middle of the area, began a volume at 22:39 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, 10.7 hours before the alert went out and 270 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.

237 
WGUS55 KSLC 192239
FFWSLC
UTC017-200130-
/O.NEW.KSLC.FF.W.0051.120819T2239Z-120820T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL GARFIELD COUNTY IN UTAH...INCLUDING THE EGYPT 3 SLOT 
  CANYON AND 25 MILE WASH

* UNTIL 730 PM MDT

* AT 430 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER THE 25 MILE WASH 
  INCLUDING EGYPT 3 AND OTHER SLOT CANYONS IN THE AREA. 

* RADAR ESTIMATES INDICATE RAINFALL TOTAL IN EXCESS OF 2 INCHES HAVE 
  FALLEN THUS FAR...WITH ADDITIONAL HEAVY RAIN EXPECTED THROUGH AT 
  LEAST 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 3766 11138 3770 11125 3754 11106 3754 11135

$$

MPS
2 follow-up statements
707 
WGUS75 KSLC 192354
FFSSLC

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

UTC017-200130-
/O.CON.KSLC.FF.W.0051.000000T0000Z-120820T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GARFIELD UT-
554 PM MDT SUN AUG 19 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM MDT FOR 25 
MILE WASH...EGYPT 3 SLOT CANYON...AND OTHER SLOT CANYONS IN SOUTH 
CENTRAL GARFIELD COUNTY...

AT 550 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATED A 
WIDESPREAD 1 TO 2 INCHES OF RAIN HAS FALLEN ACROSS THE AREA SINCE 4 
PM. RUNOFF FROM THIS RAINFALL IS LIKELY RESULTING IN A SIGNIFICANT 
FLASH FLOOD ALONG 25 MILE WASH...AS WELL AS ALL SLOT CANYONS IN THE 
AREA INCLUDING EGYPT 3. 

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 3766 11138 3770 11125 3754 11106 3754 11135

$$

MPS
222 
WGUS75 KSLC 200124
FFSSLC

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

UTC017-200132-
/O.EXP.KSLC.FF.W.0051.000000T0000Z-120820T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GARFIELD UT-
724 PM MDT SUN AUG 19 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 730 PM MDT FOR 25 MILE 
WASH...EGYPT 3 SLOT CANYON...AND OTHER SLOT CANYONS IN SOUTH CENTRAL 
GARFIELD COUNTY...

RUNOFF FROM EARLIER PRECIPITATION HAS LIKELY MADE IT THROUGH 25 MILE 
WASH AND INTO THE ESCALANTE RIVER...THUS THE FLASH FLOOD WARNING 
WILL BE ALLOWED TO EXPIRE. RADAR ESTIMATES 1 TO 2 INCHES OF RAIN 
FELL ACROSS THE 25 MILE WASH EARLIER SUNDAY AFTERNOON. 

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 3766 11138 3770 11125 3754 11106 3754 11135

$$

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, 3:52 PM MDTFlash Flood WarningSLCKane4 hr
Aug 19, 4:29 PM MDTFlash Flood WarningSLCWashington3 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.