Alert archive / Utah / Flash Flood Warnings in 2013

Flash Flood Warning 49, NWS Salt Lake City, UT

August 17, 2013Carbon County, Emery County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 17, 2013, 12:20 PM MDT for Carbon County, Emery 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 17, 2013, 12:20 PM MDT (18:20 UTC)
Expired: Aug 17, 2013, 3:15 PM MDT
In force: 3 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Flood severity: None

Counties Carbon County, UT, Emery County, UT

The radar

The Salt Lake City radar (KMTX), 224 km from the middle of the area, began a volume at 18:21 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 6.3 hours before the alert went out and 155 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 14 J/kg
Mixed-layer CIN: -352 J/kg
Mixed-layer LCL: 3591 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 104 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.

390 
WGUS55 KSLC 171820
FFWSLC
UTC007-015-172115-
/O.NEW.KSLC.FF.W.0049.130817T1820Z-130817T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1220 PM MDT SAT AUG 17 2013

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN CARBON COUNTY IN UTAH
  NORTHWESTERN EMERY COUNTY IN UTAH

* UNTIL 315 PM MDT

* AT 1212 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
HEAVY RAIN FROM A THUNDERSTORM OVER THE SEELEY BURN SCAR.

CURRENTLY AN INTENSE THUNDERSTORM IS MOVING ACROSS THE SOUTHERN EDGE 
OF THE BURN SCAR.  THIS AREA IS VERY SUSCEPTIBLE TO FLASH FLOODING 
DUE TO THE ABSENCE OF VEGETATION AND REMAINING HYDROPHOBIC SOILS 
COVERING THE WATERSHED.  THE INCREASED THREAT IS DUE TO WILDFIRE 
ACTIVITY FROM LAST SUMMER.

SR 31 IS IN DANGER OF BEING OVERTOPPED BY DEBRIS FLOWING ACROSS THE 
ROADWAY.

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 3959 11122 3962 11104 3947 11101 3935 11108
      3946 11121

$$

MCINERNEY

2 follow-up statements

392 
WGUS75 KSLC 172014
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
214 PM MDT SAT AUG 17 2013

UTC007-015-172115-
/O.CON.KSLC.FF.W.0049.000000T0000Z-130817T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CARBON UT-EMERY UT-
214 PM MDT SAT AUG 17 2013

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 PM MDT FOR
NORTHWESTERN EMERY AND SOUTHWESTERN CARBON COUNTIES...

AT 212 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE FLASH FLOODING OVER THE SEELEY BURN SCAR AND AREAS 
DOWNSTREAM TO THE HUNTINGTON POWER PLANT.

FLASH FLOODING AND DEBRIS FLOWS HAVE AFFECTED THE HUNTINGTON POWER 
PLANT...LOCATED DOWNSTREAM OF THE SEELEY BURN SCAR.  AT 
120PM...OPERATORS AT THE PLANT DIVERTED HUNTINGTON CREEK AROUND THE 
FACILITY AS IT WAS FLOWING WITH MUD AND DEBRIS.

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 3959 11122 3962 11104 3947 11101 3935 11108
      3946 11121

$$

MCINERNEY

875 
WGUS75 KSLC 172107
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
307 PM MDT SAT AUG 17 2013

UTC007-015-172116-
/O.EXP.KSLC.FF.W.0049.000000T0000Z-130817T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CARBON UT-EMERY UT-
307 PM MDT SAT AUG 17 2013

...THE FLASH FLOOD WARNING WILL EXPIRE AT 315 PM MDT FOR NORTHWESTERN
EMERY AND SOUTHWESTERN CARBON COUNTIES...

RUNOFF FROM EARLIER PRECIPITATION WILL CONTINUE TO DECREASE. A 
DEBRIS FLOW OCCURRED OFF THE SEELEY BURN SCAR AT APPROXIMATELY 120 
PM THIS AFTERNOON. WHILE CONTINUED ELEVATED RUNOFF IS POSSIBLE...THE 
THREAT OF A SIGNIFICANT DEBRIS FLOW HAS ENDED.

LAT...LON 3959 11122 3962 11104 3947 11101 3935 11108
      3946 11121

$$

KRUSE/MCINERNEY

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 2:51 AM MDT	Red Flag Warning	SLC	Box Elder, Davis, Salt Lake, Tooele, Utah	18 hr
Aug 17, 9:36 AM MDT	Flash Flood Warning	SLC	Garfield, Kane	3 hr
Aug 17, 1:19 PM MDT	Flash Flood Warning	SLC	Juab, Millard	3 hr
Aug 17, 3:14 PM MDT	Areal Flood Advisory	SLC	Utah	2 hr

Nearby

Flash Flood Warnings in Utah, 2013 Every flash flood warning in 2013

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.