Alert archive / Texas / Flash Flood Warnings in 2002

Flash Flood Warning 66, NWS Houston/Galveston, TX

December 4, 2002Galveston County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Dec 4, 2002, 6:51 AM CST for Galveston County, Texas. It was in force for 114 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Dec 4, 2002, 6:51 AM CST (12:51 UTC)
Expired: Dec 4, 2002, 8:45 AM CST
In force: 114 min
Issued by: NWS Houston/Galveston, TX
Area: Counties, with a storm outline in the text

County Galveston County, TX

The radar

The Houston radar (KHGX), 16 km from the middle of the area, began a volume at 12:54 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 0.9 hours before the alert went out and 189 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: 985 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 534 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 288 m²/s²
0-3 km storm-relative helicity: 340 m²/s²
Significant tornado parameter: 2.1
Supercell composite: 11.5

Open this sounding in Storm Lab

The text

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

000 
WGUS54 KHGX 041251
FFWHOU
TXC167-041445-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
651 AM CST WED DEC 4 2002

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLASH FLOOD WARNING EXTENDED FOR...
  GALVESTON COUNTY IN SOUTHEAST TEXAS

* UNTIL 845 AM CST

* AT 644 AM CST...DOPPLER RADAR INDICATED A LARGE AREA OF VERY HEAVY 
  RAINFALL LOCATED OVER CENTRAL GALVESTON COUNTY. RAINFALL RATES 
  APPROACHING 2 INCHES PER HOUR CAN BE EXPECTED WITH THIS BAND OF 
  RAIN. ALL OF THIS ACTIVITY WILL CONTINUE TO SAG SOUTHWARD TOWARD 
  THE COAST DURING THE NEXT COUPLE OF HOURS.

* FLOODING IS EXPECTED IN OR NEAR...
  TIKI ISLAND...TEXAS CITY...SANTA FE...SAN LEON...GALVESTON ISLAND

DO NOT CROSS ANY LOCATION WHERE WATER COVERS THE ROAD

SMALL CREEKS...STREAMS...BAYOUS...UNDERPASSES...AND FEEDER ROADS MAY
FLOOD QUICKLY. AVOID LOCATIONS WATER COVERS THE GROUND

PLEASE REPORT FLOODING TO THE COUNTY SHERIFF...LOCAL POLICE...OR
DEPARTMENT OF PUBLIC SAFETY. THEY WILL RELAY YOUR REPORT TO THE
NATIONAL WEATHER SERVICE.

LAT...LON 2952 9492 2933 9474 2914 9504 2936 9516

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this flash flood warning went out at Dec 4, 2:48 AM CST, 4 hours 3 minutes earlier.

Area forecast discussion, Dec 4, 2:48 AM CST, 4 hours 3 minutes before

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
248 AM CST WED DEC 4 2002

SQUALL LINE/COLD FRONT MAKING FAIRLY GOOD PROGRESS ACROSS THE CWA
THUS FAR THIS MORNING. CURRENT EXTRAPOLATIONS WOULD PUT THIS LINE
JUST PAST IAH AOA 15Z...TO THE COAST AOA 18Z. DRY SLOTTING BEHIND
THIS ENTIRE WX SYSTEM ALSO APPEARS TO BE MAKING SOME DECENT HEAD-
WAY IN THIS DIRECTION. MAY HAVE TO MAKE SOME ADJUSTMENTS TO CLOUD
COVER FOR THIS AFTN/EVENING TO ACCOUNT FOR THIS. POST EVENT PROGS
STILL LOOK QUIET AS THE STRONG RIDGE BUILDING DOWN THE SRN PLAINS
SETTLES OVER THE STATE. A NORTHERLY LOW-LVL FLOW SHOULD REMAIN IN
PLACE OVER SE TX THROUGH AT LEAST EARLY FRI BEFORE WINDS START TO
TURN IN RESPONSE TO THE NEXT UPPER TROF/SFC LOW COMBINATION WHICH
IS PROGGED TO CARVE OUT A VERY SIMILAR PATH INTO THE REGION LATE
SUN INTO MON. THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH THE
LONG-RANGE GUIDANCE WITH THE EVOLUTION OF EVENTS DURING THIS TIME
FRAME SO WILL LIKELY KEEP THE WORDING CLOSE TO AS IS FOR NOW. BIG
COOLDOWN STILL EXPECTED TODAY WITH TEMPS PROBABLY FALLING/HOLDING
STEADY THROUGH THE AFTN HOURS. WILL DROP THE FLASH FLOOD WATCH IN
THE NEXT PACKAGE. 41/47/45

.HGX...SCA BAYS AND 00-60NM WATERS.

PRELIMS...
CLL WB 050/034 050/031 053 600
IAH TB 060/037 051/033 053 800
GLS TB 067/043 051/040 053 +-0

Hazardous weather outlook, Dec 3, 4:50 PM CST, 14 hours 1 minute before

GMZ300-330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226
-227-235>238-041330-

HAZARDOUS WEATHER OUTLOOK...RETRANSMITTED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
450 PM CST TUE DEC 3 2002

...HEAVY RAINFALL AND SEVERE THUNDERSTORMS POSSIBLE TONIGHT AND
EARLY WEDNESDAY...

.DAY ONE...
.TONIGHT...NUMEROUS SHOWERS AND THUNDERSTORMS...POSSIBLY EVOLVING
INTO A SQUALL LINE...ARE EXPECTED TO DEVELOP THIS EVENING AS A
STRONG UPPER LEVEL DISTURBANCE INTERACTS WITH A SOUTHWARD MOVING
COLD FRONT. AGAIN...HEAVY RAINFALL AND FLASH FLOODING APPEAR TO BE
THE MAIN WEATHER THREAT. HOWEVER DUE TO THE STRONG TURNING WINDS
ALOFT...DAMAGING WINDS AND ISOLATED TORNADOES ARE ALSO POSSIBLE.

RAINFALL AMOUNTS THROUGH TONIGHT ARE EXPECTED TO AVERAGE 1 TO 2
INCHES WITH LOCALIZED 3 TO 5 INCH AMOUNTS POSSIBLE.

.SPOTTER CALL TO ACTION STATEMENT...SPOTTER ACTIVATION MAY BE
REQUIRED LATER TONIGHT.

.DAYS TWO THROUGH SEVEN...
.WEDNESDAY...HEAVY RAIN WILL PERSIST MAINLY ALONG THE COASTAL AREAS
OF SOUTHEAST TEXAS WEDNESDAY MORNING.

.THURSDAY THROUGH TUESDAY...
ANOTHER STORM SYSTEM SHOULD DEVELOP OVER THE WESTERN U.S. LATE IN
THE WEEK AND MOVE INTO SOUTHEAST TEXAS ON SUNDAY. THIS SHOULD GIVE
THE REGION ANOTHER CHANCE OF THUNDERSTORMS.

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 4, 12:57 AM CST	Severe Thunderstorm Warning	HGX		48 min
Dec 4, 4:57 AM CST	Special Marine Warning	HGX		93 min
Dec 4, 5:02 AM CST	Flash Flood Warning	HGX	Brazoria, Galveston, Harris	118 min
Dec 4, 5:37 AM CST	Special Marine Warning	HGX		2 hr
Dec 4, 5:50 AM CST	Flash Flood Warning	HGX	Chambers	115 min
Dec 4, 6:20 AM CST	Special Marine Warning	HGX		55 min
Dec 4, 7:43 AM CST	Flash Flood Warning	HGX	Chambers	62 min
Dec 4, 8:45 AM CST	Flash Flood Warning	HGX	Chambers, Galveston	3 hr

Nearby

Flash Flood Warnings in Texas, 2002 Every flash flood warning in 2002

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.