Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 28, NWS Salt Lake City, UT

July 28, 2017Garfield County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 28, 2017, 2:39 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
Jul 28, 2017, 2:39 PM MDT (20:39 UTC)
Expired
Jul 28, 2017, 5:30 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), 85 km from the middle of the area, began a volume at 20:42 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, 8.7 hours before the alert went out and 266 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 2017-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 43 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 2017-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.1939Sfc1 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
43 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
1558 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

669 
WGUS55 KSLC 282039
FFWSLC
UTC017-282330-
/O.NEW.KSLC.FF.W.0028.170728T2039Z-170728T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
239 PM MDT FRI JUL 28 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southwestern Garfield County in southern Utah...

* Until 530 PM MDT
    
* At 236 PM MDT, Doppler radar indicated a thunderstorm producing 
  heavy rain over the Henrieville Drainage.  This watershed is a 
  upper tributary to the Paria River and east of Bryce Canyon 
  National Park.

* A good portion of this drainage has received upwards of an inch of 
  rainfall in about 30 minutes.

* Flash flooding is imminent.

* If you are traveling through this area, please take immediate 
  steps to insure for your safety.


LAT...LON 3764 11184 3758 11180 3754 11204 3766 11197
      3768 11190

$$

MCINERNEY
2 follow-up statements
857 
WGUS75 KSLC 282108
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
308 PM MDT FRI JUL 28 2017

UTC017-282330-
/O.CON.KSLC.FF.W.0028.000000T0000Z-170728T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-
308 PM MDT FRI JUL 28 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MDT FOR
SOUTHWESTERN GARFIELD COUNTY...

At 306 PM MDT, Radar rainfall estimates of 1.5" in under an hour has 
fallen over Henrieville Canyon.  This area is a head water area to 
the Paria River Drainage which flows south into Arizona and the 
Colorado River.  

Henrieville Canyon is flash flood prone and with the amount of 
rainfall that has fallen, it is inferred that flash flooding is 
occurring.

Please avoid this location and many others in the area as they are 
experiencing large flash floods and should be avoided throughout the 
evening and nighttime hours.


LAT...LON 3764 11184 3758 11180 3754 11204 3766 11197
      3768 11190

$$

MCINERNEY
327 
WGUS75 KSLC 282332
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
532 PM MDT FRI JUL 28 2017

UTC017-282338-
/O.EXP.KSLC.FF.W.0028.000000T0000Z-170728T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-
532 PM MDT FRI JUL 28 2017

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN GARFIELD COUNTY WILL
EXPIRE AT 530 PM MDT...

Thunderstorm activity over the Henrieville Creek area has 
diminished.  As this is a very short reach, flash flooding from the 
earlier rainfall has moved into the Paria River mainstem flowing 
south.

As such, flash flooding in the canyon has ended.

A bit of remaining flow may still reside, please be aware if you 
come upon any dangerous areas.


LAT...LON 3764 11184 3758 11180 3754 11204 3766 11197
      3768 11190

$$

MCINERNEY

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 8:04 PM MDTFlash Flood WarningSLCKane4 hr
Jul 27, 9:24 PM MDTFlash Flood WarningSLCKane4 hr
Jul 28, 1:03 PM MDTSpecial Weather StatementSLCGarfield27 min
Jul 28, 1:15 PM MDTSpecial Weather StatementSLCGarfield30 min
Jul 28, 1:32 PM MDTSpecial Weather StatementSLCKane43 min
Jul 28, 1:38 PM MDTFlash Flood WarningSLCGarfield, Kane3 hr
Jul 28, 1:46 PM MDTFlash Flood WarningSLCGarfield5 hr
Jul 28, 2:05 PM MDTSpecial Weather StatementSLCKane25 min
Jul 28, 2:58 PM MDTFlash Flood WarningSLCGarfield, Kane, San Juan4 hr
Jul 28, 3:45 PM MDTSpecial Weather StatementSLCGarfield30 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.