Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 61, NWS Salt Lake City, UT

August 24, 2012Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 24, 2012, 7:01 PM MDT for Kane County, Utah. It was in force for 3 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: Aug 24, 2012, 7:01 PM MDT (01:01 UTC)
Expired: Aug 24, 2012, 10:00 PM MDT
In force: 3 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), 62 km from the middle of the area, began a volume at 01:01 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

Time	Report	Where	Remark
Aug 24, 7:45 PM MDT	FLASH FLOOD	9 Ene Kanab, UT	FLASH FLOOD IN JOHNSON CANYON. PARK RANGER WHO LIVES UP JOHNSON CANYON CALLED IT AVERAGE SIZE.

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 00:00Z, 1.0 hours before the alert went out and 223 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 835 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 1210 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 39 m²/s²
0-3 km storm-relative helicity: 39 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.

312 
WGUS55 KSLC 250101
FFWSLC
UTC025-250400-
/O.NEW.KSLC.FF.W.0061.120825T0101Z-120825T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
701 PM MDT FRI AUG 24 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL KANE COUNTY IN UTAH

* UNTIL 1000 PM MDT

* AT 652 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  HEAVY RAIN FROM A THUNDERSTORM OVER THE JOHNSON WASH. THIS         
  DRAINAGE IS EAST OF KANAB...AND FLOWS TO THE UTAH/ARIZONA BORDER.

* RAINFALL AMOUNTS OF 1 TO 1.5 INCHES HAS FALLEN OVER THIS DRAINAGE. 
  WITH THIS AMOUNT OF RAIN...FLASH FLOODING IS ANTICIPATED THROUGH   
  THE EVENING HOURS IN JOHNSON WASH.

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 3728 11253 3732 11233 3700 11210 3700 11246

$$

SCHOENING

1 follow-up statement

401 
WGUS75 KSLC 250354
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
954 PM MDT FRI AUG 24 2012

UTC025-250401-
/O.EXP.KSLC.FF.W.0061.000000T0000Z-120825T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KANE UT-
954 PM MDT FRI AUG 24 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1000 PM MDT FOR SOUTH
CENTRAL KANE COUNTY...

RAINFALL HAS STOPPED OVER THE JOHNSON WASH THIS EVENING...AND NO 
FURTHER RAINFALL IS EXPECTED...SO THE FLASH FLOOD WARNING WILL BE 
ALLOWED TO EXPIRE. HOWEVER...DANGEROUSLY HIGH WATER LEVELS COULD 
STILL CONTINUE IN THIS AREA THROUGH THE OVERNIGHT HOURS...AS PRIOR 
RAINFALL CONTINUES TO FLOW SOUTHWARD. 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 3728 11253 3732 11233 3700 11210 3700 11246

$$

SCHOENING

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 24, 7:39 PM MDT	Special Weather Statement	SLC		66 min

Nearby

Flash Flood Warnings in Utah, 2012 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.