Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 41, NWS Salt Lake City, UT

August 12, 2017Garfield County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 12, 2017, 12:23 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 12, 2017, 12:23 PM MDT (18:23 UTC)
Expired
Aug 12, 2017, 3:15 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), 39 km from the middle of the area, began a volume at 18:23 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, 6.4 hours before the alert went out and 290 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 2017-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 169 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 2017-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
169 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
1510 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

038 
WGUS55 KSLC 121823
FFWSLC
UTC017-122115-
/O.NEW.KSLC.FF.W.0041.170812T1823Z-170812T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
1223 PM MDT SAT AUG 12 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  West central Garfield County in southern Utah...

* Until 315 PM MDT
    
* At 1220 PM MDT, Doppler radar indicated a line of thunderstorm 
  producing heavy rain over west central Garfield County. One to two 
  inches of rain have already fallen in the last hour. Flash 
  flooding is expected to begin shortly.

* Drainages in this warning include Panguitch Creek, South Canyon, 
  Pass Creek and associated drainages.  SR-143 east of Brian Head to 
  the junction with SR12 near Panguitch is included in this warning.

* Some locations that will experience flooding include...
  Panguitch and Hillsdale. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3784 11239 3768 11236 3768 11264 3776 11263
      3785 11251

$$

CRK
4 follow-up statements
448 
WGUS55 KSLC 121825 CCA
FFWSLC
UTC017-122115-
/O.COR.KSLC.FF.W.0041.170812T1823Z-170812T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
1225 PM MDT SAT AUG 12 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  West central Garfield County in southern Utah...

* Until 315 PM MDT
    
* At 1223 PM MDT, Doppler radar indicated a line of thunderstorms 
  producing heavy rain over west central Garfield County. One to two 
  inches of rain have already fallen in the last hour. Flash 
  flooding is expected to begin shortly.

* Drainages in this warning include Panguitch Creek, South Canyon, 
  Pass Creek and associated drainages.  SR-143 east of Brian Head to 
  the junction with SR12 near Panguitch is included in this warning.

* Some locations that will experience flooding include...
  Panguitch and Hillsdale. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3784 11239 3768 11236 3768 11264 3776 11263
      3785 11251

$$

CRK
179 
WGUS55 KSLC 121826 CCB
FFWSLC
UTC017-122115-
/O.COR.KSLC.FF.W.0041.170812T1825Z-170812T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
1226 PM MDT SAT AUG 12 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  West central Garfield County in southern Utah...

* Until 315 PM MDT
    
* At 1225 PM MDT, Doppler radar indicated a line of thunderstorms 
  producing heavy rain over west central Garfield County. One to two 
  inches of rain have already fallen in the last hour. Flash 
  flooding is expected to begin shortly.

* Drainages in this warning include Panguitch Creek, South Canyon, 
  Pass Creek and associated drainages.  SR-143 east of Brian Head to 
  the junction with US-89 near Panguitch is included in this warning.

* Some locations that will experience flooding include...
  Panguitch and Hillsdale. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3784 11239 3768 11236 3768 11264 3776 11263
      3785 11251

$$

CRK
143 
WGUS75 KSLC 122016
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
216 PM MDT SAT AUG 12 2017

UTC017-122115-
/O.CON.KSLC.FF.W.0041.000000T0000Z-170812T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-
216 PM MDT SAT AUG 12 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 PM MDT FOR
WEST CENTRAL GARFIELD COUNTY...

Radar estimates of 2 to 4 inches of rain in an hour occurred across 
portions of west central Garfield County.  The heavy rainfall has 
ended at this time but flash flooding remains likely. 

This warning includes a portion of SR-143 from east of Brian Head to 
US-89 near Panguitch as well Panguitch Creek, South Canyon, Pass 
Creek and associated drainages.

Some locations that will experience flooding include...
Panguitch and Hillsdale. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3784 11239 3768 11236 3768 11264 3776 11263
      3785 11251

$$

CRK
038 
WGUS75 KSLC 122107
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
307 PM MDT SAT AUG 12 2017

UTC017-122116-
/O.EXP.KSLC.FF.W.0041.000000T0000Z-170812T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-
307 PM MDT SAT AUG 12 2017

...THE FLASH FLOOD WARNING FOR WEST CENTRAL GARFIELD COUNTY WILL
EXPIRE AT 315 PM MDT...

The heavy rain has ended across west central Garfield County. 
Enhanced runoff will continue through the afternoon.  Use caution in 
this area.

LAT...LON 3784 11239 3768 11236 3768 11264 3776 11263
      3785 11251

$$

CRK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 11:49 AM MDTFlash Flood WarningSLCIron3 hr
Aug 12, 12:44 PM MDTSpecial Weather StatementSLC46 min
Aug 12, 2:47 PM MDTFire Weather WatchSLCWashington24 hr
Aug 12, 3:15 PM MDTSevere Thunderstorm WarningSLCKane, San Juan30 min
Aug 12, 3:52 PM MDTSpecial Weather StatementSLCDuchesne38 min
Aug 12, 3:54 PM MDTSpecial Weather StatementSLC51 min
Aug 12, 4:20 PM MDTSpecial Weather StatementSLCBox Elder40 min

Nearby

Flash Flood Warnings in Utah, 2017Every flash flood warning in 2017

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.