Alert archive / Utah / Flash Flood Warnings in 2018

Flash Flood Warning 9, NWS Salt Lake City, UT

July 12, 2018Garfield County, Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 12, 2018, 3:12 PM MDT for Garfield County, Kane County, Utah. It was in force for 6 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 12, 2018, 3:12 PM MDT (21:12 UTC)
Expired
Jul 12, 2018, 9:15 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

The radar

The Cedar City radar (KICX), 85 km from the middle of the area, began a volume at 21:11 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.

What was reported inside it

TimeReportWhereRemark
Jul 12, 6:30 PM MDTFLASH FLOOD19 Nw Big Water, UTFLASH FLOOD REPORTED ALONG THE PARIA RIVER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.2 hours before the alert went out and 240 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 2018-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 47 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 2018-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
47 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
805 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

621 
WGUS55 KSLC 122112
FFWSLC
UTC017-025-130315-
/O.NEW.KSLC.FF.W.0009.180712T2112Z-180713T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
312 PM MDT THU JUL 12 2018

The National Weather Service in Salt Lake City has issued a

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

* Until 915 PM MDT Thursday
    
* At 308 PM MDT, Doppler radar indicated a thunderstorm producing 
  heavy rain over the Paria River Drainage.  Over one inch of 
  rainfall has fallen in the headwater areas, and additional 
  thunderstorms are propagating downstream.

* The lower end of this drainage has several flash flood prone areas 
  that are popular hiking areas.

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

* Some locations that will experience flooding include...
  Henrieville, Tropic, Cannonville and Kodachrome Basin State Park. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3761 11178 3736 11184 3700 11185 3700 11203
      3744 11217 3765 11209

$$

McInerney/Bonnette
2 follow-up statements
884 
WGUS75 KSLC 130128
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
728 PM MDT THU JUL 12 2018

UTC017-025-130315-
/O.CON.KSLC.FF.W.0009.000000T0000Z-180713T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
728 PM MDT THU JUL 12 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT FOR
SOUTHWESTERN GARFIELD AND CENTRAL KANE COUNTIES...

At 726 PM MDT, While thunderstorm activity has ceased over the Paria 
River Drainage, widespread flash flooding has been observed.  Many 
side canyons, in addition to the Paria Mainstem have experienced 
flash flooding.  

The extent of the flooding ranges from just below Bryce Canyon 
National Park down to the Utah/Arizona border in the drainage.

If you are recreating in the Paria Drainage, please be aware of 
elevated waterways and flooded slot canyons.

Some locations that will experience flooding include...
Henrieville, Tropic, Cannonville and Kodachrome Basin State Park. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3761 11178 3736 11184 3700 11185 3700 11203
      3744 11217 3765 11209

$$

McInerney/Bonnette
981 
WGUS75 KSLC 130312
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
912 PM MDT THU JUL 12 2018

UTC017-025-130319-
/O.EXP.KSLC.FF.W.0009.000000T0000Z-180713T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Kane UT-
912 PM MDT THU JUL 12 2018

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN GARFIELD AND CENTRAL KANE
COUNTIES WILL EXPIRE AT 915 PM MDT...

The heavy rain has ended over the Paria River drainage. High flows 
from earlier flash flooding will gradually recede through the night.

LAT...LON 3761 11178 3736 11184 3700 11185 3700 11203
      3744 11217 3765 11209

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:40 PM MDTFlash Flood WarningSLCWashington3 hr
Jul 11, 8:16 PM MDTFlash Flood WarningSLCKane, Washington2 hr
Jul 12, 5:14 PM MDTFlash Flood WarningSLCWashington4 hr
Jul 12, 5:25 PM MDTFlash Flood WarningSLCWashington3 hr

Nearby

Flash Flood Warnings in Utah, 2018Every flash flood warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.