Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 29, NWS Salt Lake City, UT

July 30, 2012Juab County, Sanpete County, Utah County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 30, 2012, 2:01 PM MDT for Juab County, Sanpete County, Utah County, Utah. It was in force for 4 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 30, 2012, 2:01 PM MDT (20:01 UTC)
Expired
Jul 30, 2012, 6:00 PM MDT
In force
4 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Juab County, UT, Sanpete County, UT, Utah County, UT

The radar

The Salt Lake City radar (KMTX), 186 km from the middle of the area, began a volume at 20:04 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.

What was reported inside it

TimeReportWhereRemark
Jul 30, 3:40 PM MDTFLASH FLOOD2 Ene Fountain Green, UTDEBRIS FLOW ORIGINATING IN THE WOOD HOLLOW BURN SCAR CROSSED SR 132 AND IMPACTED STRUCTURES WEST OF THE TOWN OF FOUNTAIN GREEN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 8.0 hours before the alert went out and 120 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, Salt Lake City I, UT at 12:00Z on 2012-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Salt Lake City I, UT at 12:00Z on 2012-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 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
12 J/kg
Mixed-layer CIN
-418 J/kg
Mixed-layer LCL
2952 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
66 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.

305 
WGUS55 KSLC 302001
FFWSLC
UTC023-039-049-310000-
/O.NEW.KSLC.FF.W.0029.120730T2001Z-120731T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
201 PM MDT MON JUL 30 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL JUAB COUNTY IN UTAH
  NORTH CENTRAL SANPETE COUNTY IN UTAH
  SOUTH CENTRAL UTAH COUNTY IN UTAH

* UNTIL 600 PM MDT

* AT 154 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  HEAVY RAIN FROM A THUNDERSTORM OVER THE WOOD HOLLOW BURN SCAR      
  ADJACENT TO THE TOWNS OF FAIRVIEW AND FOUNTAIN GREEN.

* AT THE MOST RISK FROM THIS POTENTIAL DEBRIS FLOW INCLUDE           
  STRUCTURES WITHIN THE BURN PERIMETER AND AREAS ADJACENT TO THE     
  NATURAL DRAINAGES OF THIS BURNED AREA.

IF YOU ARE WITHIN THE BURN PERIMETER...PLEASE TAKE ACTION TO         
ENSURE YOUR SAFETY.  ADDITIONALLY...IF YOU ARE NEAR THE OUTLETS OF   
THE NATURAL DRAINAGES OF THE BURN SCAR...PLEASE BE VIGILANT FOR      
DEBRIS AND MUD FLOWS EXITING THE DRAINAGE.

LAT...LON 3983 11161 3983 11144 3961 11141 3959 11166

$$

MCINERNEY
2 follow-up statements
422 
WGUS75 KSLC 302213
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
413 PM MDT MON JUL 30 2012

UTC023-039-049-310000-
/O.CON.KSLC.FF.W.0029.000000T0000Z-120731T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JUAB UT-SANPETE UT-UTAH UT-
413 PM MDT MON JUL 30 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM MDT FOR SOUTH
CENTRAL UTAH...NORTH CENTRAL SANPETE AND EAST CENTRAL JUAB
COUNTIES...

AT 406 PM MDT...A LARGE DEBRIS FLOW IS CURRENTLY FLOWING OUT OF THE 
WOOD HOLLOW BURN SCAR TOWARDS THE TOWN OF FOUNTAIN GREEN.  IT IS 
ESTIMATED THAT MANY DRAINAGES IN THE SOUTHERN END OF THE BURN SCAR 
ARE PRODUCING FLASH FLOODS.  

DAMAGE TO MULTIPLE HOMES IN THE AREA BETWEEN FOUNTAIN GREEN AND THE 
BURN SCAR HAVE BEEN REPORTED.  IT IS ALSO ANTICIPATED THAT SR 132 
WILL BE IMPACTED AS THE FLOOD MOVES WEST TOWARDS THE ROAD. 

RAINFALL AMOUNTS OF OVER 1.5 INCHES HAS BEEN REPORTED DURING THIS 
EVENT. THIS AREA IS VERY SUSCEPTIBLE TO FLASH FLOODING DUE TO THE 
RECENT FIRE ACTIVITY.

IT IS IMPORTANT THAT YOU ENSURE FOR YOUR SAFETY IF YOU ARE TRAVELING 
NEAR THIS AREA, OR ANYWHERE IN THE SOUTHERN END OF THE WOOD HOLLOW 
BURN SCAR.

LAT...LON 3983 11161 3983 11144 3961 11141 3959 11166

$$

MCINERNEY
072 
WGUS75 KSLC 310001
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
601 PM MDT MON JUL 30 2012

UTC023-039-049-310005-
/O.EXP.KSLC.FF.W.0029.000000T0000Z-120731T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JUAB UT-SANPETE UT-UTAH UT-
601 PM MDT MON JUL 30 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 600 PM MDT FOR SOUTH
CENTRAL UTAH...NORTH CENTRAL SANPETE AND EAST CENTRAL JUAB
COUNTIES...

PRECIPITATION RATES HAVE DECREASED SIGNIFICANTLY OVER THE WOOD 
HOLLOW BURN SCAR. AS A RESULT...RUNOFF HAS DIMINISHED AND THE THREAT 
OF ADDITIONAL DEBRIS FLOWS HAS DECREASED. THEREFORE...THE FLASH 
FLOOD WARNING HAS BEEN ALLOWED TO EXPIRE. CONTINUE TO MONITOR NOAA 
WEATHER RADIO OR LOCAL TELEVISION OR RADIO FOR THE LATEST WEATHER 
INFORMATION.

LAT...LON 3983 11161 3983 11144 3961 11141 3959 11166

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 3:51 AM MDTFlash Flood WatchSLC18 hr
Jul 30, 1:33 PM MDTFlash Flood WarningSLCCarbon, Emery4 hr
Jul 30, 4:32 PM MDTFlash Flood WarningSLCWashington3 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.