Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 35, NWS Salt Lake City, UT

August 5, 2017Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 5, 2017, 1:09 AM MDT for Kane County, Utah. It was in force for 4 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
Aug 5, 2017, 1:09 AM MDT (07:09 UTC)
Expired
Aug 5, 2017, 5:00 AM MDT
In force
4 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Kane County, UT

The radar

The Cedar City radar (KICX), 126 km from the middle of the area, began a volume at 07:10 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 00:00Z, 7.2 hours before the alert went out and 211 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 00:00Z on 2017-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 52 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 00:00Z on 2017-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
52 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
1381 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

588 
WGUS55 KSLC 050709
FFWSLC
UTC025-051100-
/O.NEW.KSLC.FF.W.0035.170805T0709Z-170805T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southeastern Kane County in southern Utah...

* Until 500 AM MDT
    
* At 105 AM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over much of southeastern Kane County. This includes 
  Wahweep and Warm Creek washes to where they empty into Lake 
  Powell. This area also includes the Buckskin Gulch. Flash flooding 
  is already occurring or is expected to begin shortly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3700 11231 3717 11213 3731 11182 3738 11147
      3724 11118 3711 11114 3711 11118 3705 11127
      3706 11130 3704 11129 3700 11137

$$

PW
2 follow-up statements
829 
WGUS75 KSLC 050857
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
257 AM MDT SAT AUG 5 2017

UTC025-051100-
/O.CON.KSLC.FF.W.0035.000000T0000Z-170805T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
257 AM MDT SAT AUG 5 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 AM MDT FOR
SOUTHEASTERN KANE COUNTY...

At 255 AM MDT, Doppler radar indicated another round of heavy rain 
across the eastern portions of the warned area. This will likely 
resulting in continued flash flooding on Wahweep and Warm Creek 
washes. 

The rainfall has ended across the Buckskin Gulch but flash flooding 
will likely continue in this drainage as the water moves through it. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3700 11231 3717 11213 3731 11182 3738 11147
      3724 11118 3711 11114 3711 11118 3705 11127
      3706 11130 3704 11129 3700 11137

$$

PW
709 
WGUS75 KSLC 051052
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
452 AM MDT SAT AUG 5 2017

UTC025-051100-
/O.EXP.KSLC.FF.W.0035.000000T0000Z-170805T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
452 AM MDT SAT AUG 5 2017

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN KANE COUNTY WILL EXPIRE
AT 500 AM MDT...

The heavy rain has ended and earlier flood waters are anticipated to 
continue to recede and attenuate. Flooding is no longer expected to 
pose a threat. Please continue to heed any remaining road closures.

LAT...LON 3700 11231 3717 11213 3731 11182 3738 11147
      3724 11118 3711 11114 3711 11118 3705 11127
      3706 11130 3704 11129 3700 11137

$$

GM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 2:51 AM MDTAreal Flood AdvisorySLCWashington114 min
Aug 5, 3:13 PM MDTFlash Flood WarningSLCGarfield, Iron3 hr
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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.