Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 34, NWS Shreveport, LA

August 17, 2012Smith County, Texas

NWS Shreveport, LA issued this flash flood warning at Aug 17, 2012, 8:52 AM CDT for Smith County, Texas. It was in force for 113 min. 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 17, 2012, 8:52 AM CDT (13:52 UTC)
Expired: Aug 17, 2012, 10:45 AM CDT
In force: 113 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Flood severity: None

County Smith County, TX

The radar

The Shreveport radar (KSHV), 134 km from the middle of the area, began a volume at 13:57 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 17, 9:31 AM CDT	FLASH FLOOD	Lindale, TX	FLOODING WAS REPORTED ON I20 AND FM 14

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

The nearest sounding before it

Shreveport, LA (KBAD), launched 12:00Z, 1.9 hours before the alert went out and 143 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: 112 J/kg
Mixed-layer CIN: -145 J/kg
Mixed-layer LCL: 1226 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -87 m²/s²
0-3 km storm-relative helicity: -41 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.

099 
WGUS54 KSHV 171352
FFWSHV
TXC423-171545-
/O.NEW.KSHV.FF.W.0034.120817T1352Z-120817T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
852 AM CDT FRI AUG 17 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SMITH COUNTY IN NORTHEAST TEXAS...
  THIS INCLUDES THE CITIES OF...WHITEHOUSE...TYLER...

* UNTIL 1045 AM CDT

* AT 843 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
VERY HEAVY RAIN FROM A THUNDERSTORM OVER THE WARNED AREA. RADAR 
ESTIMATES UP TO THREE IN A HALF INCHES HAS FALLEN ALREADY ACROSS THE 
AREA...AND ANOTHER INCH TO TWO INCHES IS EXPECTED IN THE NEXT HOUR 
OR TWO.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RED
  SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF UP TWO INCHES ARE POSSIBLE IN THE 
WARNED AREA.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3260 9547 3261 9533 3256 9523 3257 9521
      3254 9518 3257 9515 3255 9513 3256 9509
      3254 9508 3255 9502 3252 9501 3253 9499
      3214 9499 3215 9548 3224 9548 3229 9545
      3236 9545 3248 9559 3268 9559

$$

ELEVEN

The office that day

Everything else NWS Shreveport, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 17, 8:22 AM CDT	Areal Flood Advisory	SHV	Smith	3 hr
Aug 17, 8:38 AM CDT	Severe Thunderstorm Warning	SHV	Camp, Cass, Morris, Titus, Upshur	67 min

Nearby

Flash Flood Warnings in Texas, 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.