Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 44, NWS Salt Lake City, UT

September 14, 2017Iron County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 14, 2017, 11:15 AM MDT for Iron 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
Sep 14, 2017, 11:15 AM MDT (17:15 UTC)
Expired
Sep 14, 2017, 2:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Iron County, UT

The radar

The Cedar City radar (KICX), 20 km from the middle of the area, began a volume at 17:15 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

Las Vegas, NV (KVEF), launched 12:00Z, 5.3 hours before the alert went out and 288 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, Las Vegas, NV at 12:00Z on 2017-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 105 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, Las Vegas, NV at 12:00Z on 2017-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.19395878Sfc1 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
105 J/kg
Mixed-layer CIN
-259 J/kg
Mixed-layer LCL
2972 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

683 
WGUS55 KSLC 141715
FFWSLC
UTC021-142015-
/O.NEW.KSLC.FF.W.0044.170914T1715Z-170914T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
1115 AM MDT THU SEP 14 2017

The National Weather Service in Salt Lake City has issued a

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

* Until 215 PM MDT
    
* At 1111 AM MDT, Doppler radar indicated brief heavy rainfall has 
  fallen over the Brian Head Burn Scar.  Radar indicates that an 
  inch has fallen in a short period of time.

* Impacts include debris and flood waters on SR143 and surrounding 
  secondary roads.

* These storms are fast moving and flash flooding is expected to be 
  short lived.

* Some locations that will experience flooding include...
  Parowan and Brian Head. 

If you are traveling through this area...please take steps to ensure 
for your safety.  

LAT...LON 3775 11276 3769 11280 3769 11288 3784 11286
      3785 11281 3781 11273

$$

McInerney
1 follow-up statement
394 
WGUS75 KSLC 141823
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
1223 PM MDT THU SEP 14 2017

UTC021-142015-
/O.CON.KSLC.FF.W.0044.000000T0000Z-170914T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Iron UT-
1223 PM MDT THU SEP 14 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 215 PM MDT FOR
EAST CENTRAL IRON COUNTY...

At 1220 PM MDT, The Brian Head Burn Scar has already produced a 
debris flow crossing SR 143. Additional heavy rainfall is expected 
to move into the area around 1245pm.  This excess rainfall will 
exacerbate the flooding that is occurring.

Please stay away from this area until flooding has abated.


LAT...LON 3775 11276 3769 11280 3769 11288 3784 11286
      3785 11281 3781 11273

$$

McInerney/Verzella

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 14, 3:21 AM MDTFlash Flood WatchSLC14 hr
Sep 14, 8:29 AM MDTSpecial Weather StatementSLCWashington46 min
Sep 14, 12:21 PM MDTSpecial Weather StatementSLCKane24 min
Sep 14, 12:22 PM MDTSpecial Weather StatementSLCKane23 min
Sep 14, 12:39 PM MDTSpecial Weather StatementSLCGarfield36 min
Sep 14, 12:50 PM MDTSpecial Weather StatementSLCKane25 min
Sep 14, 12:51 PM MDTFlash Flood WarningSLCKane, Washington4 hr
Sep 14, 1:18 PM MDTSpecial Weather StatementSLCGarfield27 min
Sep 14, 1:55 PM MDTSpecial Weather StatementSLCKane35 min
Sep 14, 2:11 PM MDTSpecial Weather StatementSLC64 min
Sep 14, 2:15 PM MDTFlash Flood WarningSLCKane8 hr
Sep 14, 2:20 PM MDTFlash Flood WarningSLCGarfield, Kane, Wayne3 hr
Sep 14, 2:39 PM MDTSpecial Weather StatementSLCWayne66 min
Sep 14, 2:52 PM MDTSevere Thunderstorm WarningSLCEmery, Garfield, Wayne38 min
Sep 14, 3:05 PM MDTFlash Flood WarningSLCGarfield3 hr

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.