Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 6, NWS Amarillo, TX

August 20, 2012Potter County, Texas

NWS Amarillo, TX issued this flash flood warning at Aug 20, 2012, 7:55 PM CDT for Potter County, Texas. It was in force for 113 min. 4 reports 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 20, 2012, 7:55 PM CDT (00:55 UTC)
Expired
Aug 20, 2012, 9:48 PM CDT
In force
113 min
Issued by
NWS Amarillo, TX
Area
Storm-based polygon
Flood severity
None

County Potter County, TX

The radar

The Amarillo radar (KAMA), 32 km from the middle of the area, began a volume at 00:56 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
Aug 20, 7:58 PM CDTFLASH FLOODAmarillo, TXRESIDENTAL STREETS FLOODED AND IMPASSIBLE NEAR DOWNTOWN
Aug 20, 8:00 PM CDTFLASH FLOOD1 E Amarillo, TXUNDERPASSES NEAR INTERSTATE 40 AND SOUTH GRANT ARE FLOODED. TIME ESTIMATED.
Aug 20, 8:00 PM CDTFLASH FLOOD6 Wnw Amarillo, TXROADS FLOODED NEAR MEDI PARK. TIME ESTIMATED.
Aug 20, 8:09 PM CDTFLASH FLOODAmarillo, TXEMERGENCY MANAGER REPORTED NUMEROUS FLOODED INTERSECTIONS AND VEHICLES STRANDED WITH WATER RESCUES BEING CONDUCTED.

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

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 0.9 hours before the alert went out and 33 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, Amarillo Airport, TX at 00:00Z on 2012-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 284 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 00:00Z on 2012-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.1939587897Sfc1 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
284 J/kg
Mixed-layer CIN
-120 J/kg
Mixed-layer LCL
2322 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
317 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.5

Open this sounding in Storm Lab

The text

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

606 
WGUS54 KAMA 210055
FFWAMA
TXC375-210400-
/O.NEW.KAMA.FF.W.0006.120821T0055Z-120821T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AMARILLO TX
755 PM CDT MON AUG 20 2012

THE NATIONAL WEATHER SERVICE IN AMARILLO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  POTTER COUNTY IN THE PANHANDLE OF TEXAS...
  THIS INCLUDES THE CITY OF AMARILLO...

* UNTIL 1100 PM CDT

* AT 754 PM CDT... LOCAL EMERGENCY MANAGEMENT OFFICIALS REPORTED   
FLASH FLOODING ALONG INTERSTATE 40 IN AND AROUND AMARILLO

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL RESULT IN HIGH WATER LEVELS
AT UNDERPASSES ALONG INTERSTATE 40. MOTORISTS ARE STRONGLY URGED TO 
REDUCE SPEEDS ON INTERSTATE 40 AND BE PREPARED TO BE DIVERTED OFF 
THE INTERSTATE SHOULD HIGH WATER BE OBSERVED.

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. MOVE TO HIGHER GROUND.

TO REPORT FLOODING...PLEASE CALL THE NATIONAL WEATHER SERVICE AT 8 0
6 3 3 5 1 1 2 1.

&&

LAT...LON 3562 10217 3562 10162 3519 10163 3519 10217

$$

MOULTON
1 follow-up statement
003 
WGUS74 KAMA 210248
FFSAMA

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AMARILLO TX
948 PM CDT MON AUG 20 2012

TXC375-210258-
/O.CAN.KAMA.FF.W.0006.000000T0000Z-120821T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
POTTER TX-
948 PM CDT MON AUG 20 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR POTTER COUNTY...

NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED RAINFALL WAS ENDING
ACROSS THE WARNED AREA...AND THE FLASH FLOOD THREAT WAS DIMINISHING.
SOME MINOR FLOODING MAY CONTINUE...BUT THE THREAT OF SERIOUS FLOODING
IS ENDING. THUS...THE FLASH FLOOD WARNING HAS BEEN CANCELLED.

LAT...LON 3562 10217 3562 10162 3519 10163 3519 10217

$$

MOULTON

The office that day

Everything else NWS Amarillo, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 20, 7:17 PM CDTAreal Flood AdvisoryAMARandall6 hr
Aug 20, 7:25 PM CDTSevere Thunderstorm WarningAMADeaf Smith, Randall50 min
Aug 20, 7:32 PM CDTSevere Thunderstorm WarningAMACarson, Hutchinson, Moore, Potter58 min
Aug 20, 7:48 PM CDTFlash Flood WarningAMARandall118 min
Aug 20, 7:49 PM CDTSevere Thunderstorm WarningAMAArmstrong, Randall56 min
Aug 20, 8:02 PM CDTAreal Flood AdvisoryAMAArmstrong, Carson, Hutchinson4 hr
Aug 20, 8:31 PM CDTSevere Thunderstorm WarningAMAArmstrong, Carson, Donley, Gray43 min
Aug 20, 8:51 PM CDTAreal Flood AdvisoryAMADonley4 hr

Nearby

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