Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 13, NWS Salt Lake City, UT

July 21, 2017Garfield County, Kane County, San Juan County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 21, 2017, 2:08 PM MDT for Garfield County, Kane County, San Juan County, Utah. It was in force for 6 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 21, 2017, 2:08 PM MDT (20:08 UTC)
Expired
Jul 21, 2017, 8:00 PM MDT
In force
6 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Garfield County, UT, Kane County, UT, San Juan County, UT

The radar

The Cedar City radar (KICX), 83 km from the middle of the area, began a volume at 20:10 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, 8.1 hours before the alert went out and 239 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 2017-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 65 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 2017-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
65 J/kg
Mixed-layer CIN
-58 J/kg
Mixed-layer LCL
1286 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

876 
WGUS55 KSLC 212008
FFWSLC
UTC017-025-037-220200-
/O.NEW.KSLC.FF.W.0013.170721T2008Z-170722T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
208 PM MDT FRI JUL 21 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southwestern Garfield County in southern Utah...
  Southwestern San Juan County in southeastern Utah...
  Central Kane County in southern Utah...

* Until 800 PM MDT
    
* At 203 PM MDT, Doppler radar indicated a thunderstorm producing 
  heavy rain over the Cottonwood, Paria, Buckskin, Wahweap Creek, 
  House Rock Valley Road, and a few other additional drainages. Up 
  to one inch of rain has already fallen. Flash flooding is expected 
  to begin shortly.

* Some locations that will experience flooding include...
  Big Water, Henrieville, Cannonville, Kodachrome Basin State Park
  and Lake Powell.

* If you are traveling in this area, please take appropriate actions 
  to ensure your safety. 

LAT...LON 3768 11188 3701 11134 3700 11219 3737 11230
      3754 11216

$$

Mcinerney/Lukinbeal
2 follow-up statements
776 
WGUS75 KSLC 212140
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
340 PM MDT FRI JUL 21 2017

UTC017-025-037-220200-
/O.CON.KSLC.FF.W.0013.000000T0000Z-170722T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-San Juan UT-Kane UT-
340 PM MDT FRI JUL 21 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 PM MDT FOR
SOUTHWESTERN GARFIELD...SOUTHWESTERN SAN JUAN AND CENTRAL KANE
COUNTIES...

At 333 PM MDT, Thunderstorm activity continues over the Paria, 
Buckskin, Cottonwood, Wahweap drainages including the House Rock 
Road.  The amount and intensity of the rainfall falling over these 
areas is expected to produce significant flash flooding across all 
drainages under the warning.

If you are traveling in the vicinity of the warning, please take 
appropriate action to ensure for your safety. 

Some locations that will experience flooding include...
Big Water, Henrieville, Cannonville, Kodachrome Basin State Park and
Lake Powell.

LAT...LON 3768 11188 3701 11134 3700 11219 3737 11230
      3754 11216

$$

MCINERNEY
676 
WGUS75 KSLC 220151
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
751 PM MDT FRI JUL 21 2017

UTC017-025-037-220200-
/O.CON.KSLC.FF.W.0013.000000T0000Z-170722T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-San Juan UT-Kane UT-
751 PM MDT FRI JUL 21 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 PM MDT FOR
SOUTHWESTERN GARFIELD...SOUTHWESTERN SAN JUAN AND CENTRAL KANE
COUNTIES...

At 747 PM MDT, Flash flooding has been reported in the Paria River 
Drainage.  The Cottonwood Road has been damaged and closed due to 
the flooding.  Other drainages have also experienced flash flooding. 
Thunderstorm activity in the area has diminished.

It is anticipated the main flows will pass the Utah/Arizona border 
this evening. However, elevated flows and muddy conditions will 
remain through tomorrow.

If you are traveling through the Southern end of the Grand Staircase 
Escalante National Monument on dirt roads, be prepared for 
challenging conditions.

LAT...LON 3768 11188 3701 11134 3700 11219 3737 11230
      3754 11216

$$

MCINERNEY

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 7:26 PM MDTSevere Thunderstorm WarningSLCTooele49 min
Jul 20, 8:41 PM MDTSpecial Weather StatementSLCJuab49 min
Jul 21, 1:14 PM MDTFlash Flood WarningSLCGarfield, Kane, San Juan4 hr
Jul 21, 2:06 PM MDTSpecial Weather StatementSLCDuchesne24 min
Jul 21, 5:29 PM MDTAreal Flood AdvisorySLCCarbon61 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.