Alert archive / Utah / Flash Flood Warnings in 2011

Flash Flood Warning 12, NWS Salt Lake City, UT

July 25, 2011Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 25, 2011, 6:54 PM MDT for Washington 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 25, 2011, 6:54 PM MDT (00:54 UTC)
Expired: Jul 26, 2011, 12:45 AM MDT
In force: 6 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Flood severity: None

County Washington County, UT

The radar

The Cedar City radar (KICX), 83 km from the middle of the area, began a volume at 00:55 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

Las Vegas, NV (KVEF), launched 00:00Z, 0.9 hours before the alert went out and 196 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 4095 m above ground
0-6 km bulk shear: 0 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 0 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.

875 
WGUS55 KSLC 260054
FFWSLC
UTC053-260645-
/O.NEW.KSLC.FF.W.0012.110726T0054Z-110726T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
654 PM MDT MON JUL 25 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

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

* UNTIL 1245 AM MDT

* AT 636 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM STATIONARY THUNDERSTORMS OVER EXTREME 
  NORTHWEST ARIZONA. THE RUNOFF FROM THIS HEAVY RAIN WILL FLOW 
  THROUGH THE FORT PIERCE WASH ACROSS EXTREME SOUTHERN WASHINGTON 
  COUNTY. THE FLOODING THREAT WILL EXTEND TO THE VIRGIN RIVER IN 
  THE ST. GEORGE AREA SHORTLY AFTER MIDNIGHT TONIGHT

* THE STORM PRODUCING FLASH FLOODING WILL REMAIN OVER RURAL AREAS 
  OF THE INDICATED COUNTY THIS EVENING.
  

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.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

&&

LAT...LON 3708 11359 3709 11356 3702 11350 3702 11338
      3700 11337 3700 11354

$$

CONGER

2 follow-up statements

741 
WGUS75 KSLC 260349
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
949 PM MDT MON JUL 25 2011

UTC053-260645-
/O.CON.KSLC.FF.W.0012.000000T0000Z-110726T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
949 PM MDT MON JUL 25 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1245 AM MDT FOR
SOUTH CENTRAL WASHINGTON COUNTY...

AT 942 PM MDT...LIGHT SHOWERS CONTINUE TO MOVE NORTH THROUGH THE 
WARNED AREA. THE VERY HEAVY RAINFALL FROM EARLIER THIS EVENING HAS 
LIKELY GENERATED FLASH FLOODING THROUGH THE FORT PIERCE WASH THIS 
EVENING. THE FLASH FLOODING GENERATED FROM THE HEAVY RUNOFF WILL 
LIKELY WILL REACH THE ST GEORGE AREA AROUND MIDNIGHT TONIGHT. 

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.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 3708 11359 3709 11356 3702 11350 3702 11338
      3700 11337 3700 11354

$$

CONGER

219 
WGUS75 KSLC 260654
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1254 AM MDT TUE JUL 26 2011

UTC053-260702-
/O.EXP.KSLC.FF.W.0012.000000T0000Z-110726T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-
1254 AM MDT TUE JUL 26 2011

...THE FLASH FLOOD WARNING HAS EXPIRED FOR THE FORT PEARCE WASH IN 
SOUTH CENTRAL WASHINGTON COUNTY...

REPORTS FROM ST GEORGE POLICE INDICATE NO FLASH FLOODING IS 
OCCURRING ON THE FT PEARCE WASH. THEREFORE... THE FLASH FLOOD 
WARNING HAS BEEN ALLOWED TO EXPIRE. MONITOR NOAA WEATHER RADIO OR 
LOCAL TELEVISION OR RADIO FOR THE LATEST WEATHER INFORMATION.

LAT...LON 3708 11359 3709 11356 3702 11350 3702 11338
      3700 11337 3700 11354

$$

SEAMAN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 26, 3:36 AM MDT	Flash Flood Watch	SLC		18 hr
Jul 26, 1:05 PM MDT	Areal Flood Advisory	SLC	Washington	115 min
Jul 26, 2:34 PM MDT	Areal Flood Advisory	SLC	Kane	3 hr
Jul 26, 2:50 PM MDT	Flash Flood Warning	SLC	Kane	5 hr
Jul 26, 3:26 PM MDT	Severe Thunderstorm Warning	SLC	Salt Lake, Utah	31 min
Jul 26, 3:37 PM MDT	Areal Flood Advisory	SLC	Salt Lake	3 hr
Jul 26, 4:05 PM MDT	Flash Flood Warning	SLC	Salt Lake	3 hr
Jul 26, 4:40 PM MDT	Areal Flood Advisory	SLC	Salt Lake, Utah	110 min

Nearby

Flash Flood Warnings in Utah, 2011 Every flash flood warning in 2011

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.