Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 27, NWS Salt Lake City, UT

July 28, 2017Garfield County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 28, 2017, 1:46 PM MDT for Garfield County, Utah. It was in force for 5 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, 1:46 PM MDT (19:46 UTC)
Expired
Jul 28, 2017, 6:45 PM MDT
In force
5 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), 118 km from the middle of the area, began a volume at 19:48 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, 7.8 hours before the alert went out and 278 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.

231 
WGUS55 KSLC 281946
FFWSLC
UTC017-290045-
/O.NEW.KSLC.FF.W.0027.170728T1946Z-170729T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Salt Lake City has issued a

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

* Until 645 PM MDT
    
* At 142 PM MDT, Doppler radar indicated a thunderstorm producing 
  heavy rain over the headwaters of the Escalante River just north 
  and west of the town of Escalante. Some of these drainages include 
  North, Deep, Caanan, Harris and a few others in the area.

* Radar rainfall estimates indicate a wide swath of rainfall around 
  an inch has fallen. As such, it is anticipated that flash flooding 
  will begin shortly.

* If you are traveling through these areas, please take precautions 
  to ensure for your safety.  

LAT...LON 3786 11157 3777 11136 3766 11120 3762 11131
      3760 11147 3760 11164 3765 11185 3786 11185

$$

MCINERNEY
2 follow-up statements
882 
WGUS75 KSLC 282204
FFSSLC

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

UTC017-290045-
/O.CON.KSLC.FF.W.0027.000000T0000Z-170729T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-
404 PM MDT FRI JUL 28 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MDT FOR
SOUTH CENTRAL GARFIELD COUNTY...

At 359 PM MDT, Thunderstorm activity in the Escalante headwater area 
has slowed significantly.  However, radar rainfall estimates for 
this area show that widespread inch or more of precipitation has 
fallen across multiple headwater areas.  As such, it is inferred 
that flash flooding is occurring across many drainages.

Headwater areas that have accumulated over an inch in under an hour 
include Alvey, Harris, Canaan, and several others in the area.

Please be aware of the dangerous conditions that that are occurring 
across the Escalante headwater areas.  Additionally, as the runoff 
from all this rain continues, downstream areas of the Escalante will 
become hazardous this evening and into the night time hours.

LAT...LON 3786 11157 3777 11136 3766 11120 3762 11131
      3760 11147 3760 11164 3765 11185 3786 11185

$$

MCINERNEY
927 
WGUS75 KSLC 290039
FFSSLC

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

UTC017-290045-
/O.EXP.KSLC.FF.W.0027.000000T0000Z-170729T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-
639 PM MDT FRI JUL 28 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL GARFIELD COUNTY WILL
EXPIRE AT 645 PM MDT...

The flash flood threat for the Escalante headwaters areas including 
Alvey, Upper Valley, Escalante, North Creek and Harris washes has 
been diminished due to a combination of lesser rainfall and 
attenuating flows.

However, due to scattered nature of the thunderstorm activity in the 
area and residual flows, please stay away from these areas until 
Saturday morning. 


LAT...LON 3786 11157 3777 11136 3766 11120 3762 11131
      3760 11147 3760 11164 3765 11185 3786 11185

$$

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, 2:05 PM MDTSpecial Weather StatementSLCKane25 min
Jul 28, 2:39 PM MDTFlash Flood WarningSLCGarfield3 hr
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.