Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 54, NWS Salt Lake City, UT

August 20, 2012Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 20, 2012, 5:13 PM MDT for Kane County, Utah. It was in force for 7 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 20, 2012, 5:13 PM MDT (23:13 UTC)
Expired
Aug 21, 2012, 12:15 AM MDT
In force
7 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), 94 km from the middle of the area, began a volume at 23:14 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, 11.2 hours before the alert went out and 210 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 2012-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 808 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 2012-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.193958Sfc1 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
808 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
974 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
5 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

649 
WGUS55 KSLC 202313
FFWSLC
UTC025-210615-
/O.NEW.KSLC.FF.W.0054.120820T2313Z-120821T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
513 PM MDT MON AUG 20 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL KANE COUNTY IN UTAH INCLUDING THE PARIA RIVER AND 
  BUCKSKIN GULCH. 

* UNTIL 1215 AM MDT

* AT 510 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  HEAVY RAIN HAS FALLEN ACROSS THE PARIA AND BUCKSKIN GULCH 
  DRAINAGES...RESULTING FROM MULTIPLE THUNDERSTORMS MOVING ACROSS 
  THE SAME AREA. 

* THESE STORMS ARE EXPECTED TO CONTINUE REDEVELOPING AND MOVING 
  ACROSS SOUTH CENTRAL KANE COUNTY THROUGH AT LEAST 6 PM...BRINGING
  ADDITIONAL HEAVY RAIN TO THE PARIA AND BUCKSKIN GULCH AREAS. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 3700 11201 3723 11219 3730 11200 3726 11190
      3700 11184 3700 11193

$$

MPS
1 follow-up statement
377 
WGUS75 KSLC 210208
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
808 PM MDT MON AUG 20 2012

UTC025-210615-
/O.CON.KSLC.FF.W.0054.000000T0000Z-120821T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-
808 PM MDT MON AUG 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 AM MDT FOR
SOUTH CENTRAL KANE COUNTY...

AT 800 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATED 
0.75 TO 1.25 INCHES OF RAIN HAD FALLEN LATE MONDAY AFTERNOON ACROSS 
THE HEADWATERS OF THE PARIA RIVER DRAINAGE...PRIMARILY ACROSS 
COTTONWOOD CANYON. THIS RAINFALL HAS ENDED...HOWEVER EXCESSIVE 
RUNOFF FROM THIS RAINFALL IS LIKELY MAKING ITS WAY DOWN THE PARIA 
RIVER...AND SHOULD PASS UNDER THE HIGHWAY 89 BRIDGE BY 10 PM. 

PEOPLE ARE STRONGLY ENCOURAGED TO STAY AWAY FROM THE PARIA RIVER 
THIS EVENING AS THIS FLOOD MAKES ITS WAY DOWNSTREAM. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 3700 11201 3723 11219 3730 11200 3726 11190
      3700 11184 3700 11193

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 4:54 AM MDTFlash Flood WatchSLC15 hr
Aug 20, 3:06 PM MDTRed Flag WarningSLCBox Elder, Davis, Juab, Millard, Salt Lake, Sanpete and 2 more33 hr

Nearby

Flash Flood Warnings in Utah, 2012Every flash flood warning in 2012

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.