Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 36, NWS Salt Lake City, UT

August 5, 2017Garfield County, Iron County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 5, 2017, 3:13 PM MDT for Garfield County, Iron County, Utah. It was in force for 3 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
Aug 5, 2017, 3:13 PM MDT (21:13 UTC)
Expired
Aug 5, 2017, 6:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Garfield County, UT, Iron County, UT

The radar

The Cedar City radar (KICX), 22 km from the middle of the area, began a volume at 21:16 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
Aug 5, 4:30 PM MDTFLASH FLOOD11 Wnw Hatch, UTBOULDERES ACROSS THE ROAD ALONG STATE ROUTE 143 NEAR WHITE BRIDGE CAMPGROUND IN THE PANGUITCH CREEK DRAINAGE. A FRONT LOADER WAS NEEDED TO REMOVE THE BOULDERS.

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

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.2 hours before the alert went out and 287 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 2017-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 14 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 2017-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 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
14 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
1168 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
24 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

773 
WGUS55 KSLC 052113
FFWSLC
UTC017-021-060015-
/O.NEW.KSLC.FF.W.0036.170805T2113Z-170806T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
313 PM MDT SAT AUG 5 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Western Garfield County in southern Utah...
  East central Iron County in southern Utah...

* Until 615 PM MDT
    
* At 311 PM MDT, Doppler radar indicated a thunderstorm producing 
  heavy rain over the Brian Head burnscar specifically the Panguitch 
  and Clear Creek drainages. Up to one inch of rain has already 
  fallen. Flash flooding is expected to begin shortly.

* Flash flooding will remain over mainly rural areas of western
  Garfield and east central Iron Counties.
  Excessive rainfall over the Brian Head burn scar will result in 
  debris flow moving through the Panguitch/Clear Creek drainages, 
  including SR-143. The debris flow can consist of rock, mud, 
  vegetation and other loose materials.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If a debris flow has occurred it is important to realize that the
runout area remains very dangerous. Additional debris flows may occur
within minutes of the original flow. Please remain vigilant and be
prepared to take swift action.

&&

LAT...LON 3768 11265 3772 11277 3777 11268 3773 11258

$$

NC
2 follow-up statements
521 
WGUS75 KSLC 052247
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
447 PM MDT SAT AUG 5 2017

UTC017-021-060015-
/O.CON.KSLC.FF.W.0036.000000T0000Z-170806T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Iron UT-
447 PM MDT SAT AUG 5 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MDT FOR
WESTERN GARFIELD AND EAST CENTRAL IRON COUNTIES...

As of 438 PM MDT, heavy precipitation has come to an end over the 
warned area however flash flooding may still be occurring due to the 
2 inches of precipitation which fell over the previous 2 hours. 

Flash flooding will remain over mainly rural areas of western 
Garfield and east central Iron Counties. Excessive rainfall over the 
Brian Head burn scar will result in debris flow moving through the 
Panguitch/Clear Creek drainages, including SR-143. The debris flow 
can consist of rock, mud, vegetation and other loose materials.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If a debris flow has occurred it is important to realize that the
runout area remains very dangerous. Additional debris flows may occur
within minutes of the original flow. Please remain vigilant and be
prepared to take swift action.

&&

LAT...LON 3768 11265 3772 11277 3777 11268 3773 11258

$$

NC
276 
WGUS75 KSLC 060011
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
611 PM MDT SAT AUG 5 2017

UTC017-021-060017-
/O.EXP.KSLC.FF.W.0036.000000T0000Z-170806T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Iron UT-
611 PM MDT SAT AUG 5 2017

...THE FLASH FLOOD WARNING FOR WESTERN GARFIELD AND EAST CENTRAL IRON
COUNTIES WILL EXPIRE AT 615 PM MDT...

The heavy rain has ended in the eastern part of the Brian Head burn 
scar and flash flooding is no longer considered a threat. However, 
creeks and streams as well as normally dry washes will continue to 
see high flows through late tonight as any flood waters from earlier 
heavy rain gradually recede. Please continue to heed any remaining 
road closures.

LAT...LON 3768 11265 3772 11277 3777 11268 3773 11258

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 1:09 AM MDTFlash Flood WarningSLCKane4 hr
Aug 5, 2:51 AM MDTAreal Flood AdvisorySLCWashington114 min
Aug 5, 5:20 PM MDTSpecial Weather StatementSLCCarbon25 min
Aug 5, 5:44 PM MDTSpecial Weather StatementSLCEmery31 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.