Alert archive / Utah / Flash Flood Warnings in 2011

Flash Flood Warning 33, NWS Salt Lake City, UT

August 19, 2011Garfield County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 19, 2011, 6:12 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, 2011, 6:12 PM MDT (00:12 UTC)
Expired
Aug 19, 2011, 9:15 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), 211 km from the middle of the area, began a volume at 00:15 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

Grand Junction, CO (KGJT), launched 00:00Z, 0.2 hours before the alert went out and 216 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, Grand Junction, CO at 00:00Z on 2011-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 96 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 00:00Z on 2011-08-20The 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
96 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
3221 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
31 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.

486 
WGUS55 KSLC 200012
FFWSLC
UTC017-200315-
/O.NEW.KSLC.FF.W.0033.110820T0012Z-110820T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
612 PM MDT FRI AUG 19 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

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

* UNTIL 915 PM MDT

* AT 602 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
HEAVY RAIN FROM A THUNDERSTORM OVER HIGHWAY 95 IN EAST CENTRAL 
GARFIELD COUNTY. THE HEAVY RAIN HAS THE POTENTIAL TO CAUSE FLASH 
FLOODING ALONG NORTH WASH...WHICH RUNS PARALLEL TO HIGHWAY 95 BEFORE 
DRAINING INTO LAKE POWELL NEAR HITE MARINA.

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 3812 11059 3801 11044 3800 11039 3790 11038
      3786 11041 3792 11055 3796 11061 3804 11065

$$

LC
2 follow-up statements
282 
WGUS75 KSLC 200144
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
744 PM MDT FRI AUG 19 2011

UTC017-200315-
/O.CON.KSLC.FF.W.0033.000000T0000Z-110820T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GARFIELD UT-
744 PM MDT FRI AUG 19 2011

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

AT 736 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT HEAVY RAIN HAS ENDED OVER THE WARNED AREA. HOWEVER...OVER ONE 
AND A HALF INCHES OF RAIN HAS FALLEN ALONG NORTH WASH...WHICH RUNS 
ALONGSIDE HIGHWAY 95 BEFORE DRAINING INTO LAKE POWELL NEAR HITE 
MARINA. THIS AMOUNT OF RAIN IS CAPABLE OF PRODUCING FLASH FLOODING 
ALONG NORTH WASH AND ADJACENT AREAS.

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 3812 11059 3801 11044 3800 11039 3790 11038
      3786 11041 3792 11055 3796 11061 3804 11065

$$

LC
133 
WGUS75 KSLC 200307
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
907 PM MDT FRI AUG 19 2011

UTC017-200316-
/O.EXP.KSLC.FF.W.0033.000000T0000Z-110820T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GARFIELD UT-
907 PM MDT FRI AUG 19 2011

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

RAIN HAS ENDED ACROSS THE WARNED AREA. RUNOFF FROM THE HEAVY RAIN 
EARLIER WILL CONTINUE TO DECREASE THROUGH LATE THIS 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 3812 11059 3801 11044 3800 11039 3790 11038
      3786 11041 3792 11055 3796 11061 3804 11065

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 1:27 PM MDTFlash Flood WarningSLCGarfield3 hr
Aug 20, 2:44 PM MDTAreal Flood AdvisorySLCGarfield3 hr
Aug 20, 4:30 PM MDTAreal Flood AdvisorySLCGarfield, Kane3 hr

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.