Alert archive / Texas / Flash Flood Warnings in 2001

Flash Flood Warning 55, NWS Houston/Galveston, TX

June 9, 2001Harris County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Jun 9, 2001, 2:57 PM CDT for Harris County, Texas. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Jun 9, 2001, 2:57 PM CDT (19:57 UTC)
Expired
Jun 9, 2001, 6:00 PM CDT
In force
3 hr
Issued by
NWS Houston/Galveston, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Harris County, TX

The radar

The Houston radar (KHGX), 23 km from the middle of the area, began a volume at 20:00 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.0 hours before the alert went out and 194 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, Lake Charles Mun, LA at 12:00Z on 2001-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2262 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 12:00Z on 2001-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.1939Sfc1 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
2262 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
451 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
82 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.

000 
WGUS54 KHGX 091957
FFWHOU
TXC201-092300-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
257 PM CDT SAT JUN 9 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN HARRIS COUNTY IN SOUTHEAST TEXAS

* UNTIL 600 PM CDT

* AT 255 PM CDT...DOPPLER RADAR INDICATED VERY HEAVY RAINFALL.
  SHOWERS AND THUNDERSTORMS DEVELOPING OVER COASTAL COUNTIES WILL    
  PIVOT INTO SOUTHERN HARRIS COUNTY LATE THIS AFTERNOON AND EVENING.
  DUE TO SATURATED GROUND...ANY ADDITIONAL RAINFALL WILL COMPLICATE  
  THE FLOOD THREAT.  EXPECT ANOTHER 1 TO 2 INCHES OF RAIN BY 6 PM.

* FLOODING IS EXPECTED IN OR NEAR...
  WEBSTER...CLEAR LAKE AND LA PORTE

DO NOT CROSS ANY LOCATION WHERE WATER COVERS THE ROAD

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 2965 9529 2952 9514 2969 9493 2983 9508

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 Jun 9, 2:50 PM CDT, 7 minutes earlier.

Area forecast discussion, Jun 9, 2:50 PM CDT, 7 minutes before
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
250 PM CDT SAT JUN 9 2001

...DANGEROUS FLASH FLOOD THREAT PERSISTS ACROSS SOUTHEAST TEXAS...
...AVERAGE RAINFALL AMOUNTS THROUGH TONIGHT EXPECTED TO BE 3 TO 5
INCHES WITH ISOLATED 10 TO 15 INCH TOTALS POSSIBLE...

SOUTHEAST TEXAS IS STILL UNDER AN EXTREMELY DANGEROUS FLASH FLOOD
THREAT AS SHOWERS AND THUNDERSTORMS HAVE BEGUN TO FIRE AGAIN THIS
AFTERNOON. THE CIRCULATION CENTER AT THE SURFACE IS IN THE VICINITY
OF THE BRAZORIA-MATAGORDA COUNTY LINE. WILL CONTINUE TO CLOSELY
MONITOR THE CIRCULATION CENTER AND FOLLOW THE TPC PRODUCTS AND
DISCUSSIONS CONCERNING POSSIBLE REDEVELOPMENT OF ALLISON. MORE
IMPORTANTLY AT THE MOMENT IS THE CONVECTION THAT HAS BEEN FIRING
DURING THE PAST HOUR ACROSS THE COASTAL COUNTIES. A SOLID LINE OF
SHOWERS AND THUNDERSTORMS (WITH STEADILY COOLING CLOUD TOPS AND
INCREASING LIGHTNING STRIKES) STRETCHES FROM WINNIE TO PASADENA TO
FRIENDSWOOD TO PEARLAND TO NEAR NEEDVILLE. THERE APPEARS TO BE A
WEAK CONVERGENCE ZONE AT THE SURFACE SETTING UP ALONG THIS BOUNDARY
WHICH WOULD SUPPORT A CONTINUATION AND EXPANSION OF THESE STORMS FOR
THE NEXT SEVERAL HOURS OVER THE SAME AREA. AS A RESULT...SERIOUS
FLOODING HAS LIKELY BEGUN AGAIN WILL CALL FOR 3 TO 5 INCH RAINFALL
AVERAGES WITH SOME 10 TO 15 INCH TOTALS...OR MORE...LIKELY BY
TOMORROW MORNING

DUE TO POTENTIAL REDEVELOPMENT OF ALLISON...EXTREME RAINFALL RUNOFF
INTO GALVESTON BAY AND THE UPPER COAST...AND ABOVE NORMAL TIDES...
WILL ISSUE A COASTAL FLOOD WATCH FROM HIGH ISLAND TO FREEPORT AND
THE COASTAL SECTIONS OF GALVESTON BAY.

RAINS BEYOND TONIGHT WILL DEPEND ON THE POSSIBLE REDEVELOPMENT OF
ALLISON. FOR NOW...WILL CONTINUE TO CALL FOR GRADUALLY DECREASING
POPS AREAWIDE ON SUNDAY AND MONDAY AS MODELS TAKE THE SYSTEM OFF TO
THE EAST.

42/47/48/43/TF/KM

.HGX...FLASH FLOOD WATCH ALL OF SOUTHEAST TEXAS THROUGH TONIGHT.
       COASTAL FLOOD WATCH HIGH ISLAND TO FREEPORT AND THE COASTAL
       SECTIONS OF GALVESTON BAY.
       SCA GULF WATERS.

PRELIMS...
CLL TE 071/088 072/089 072 541
IAH TT 072/086 072/086 072 962
GLS TT 075/084 075/084 075 +73

In the hours before

Special weather statement, Jun 9, 2:00 PM CDT, 57 minutes before
TXZ163-164-176>179-195>200-210>214-226-227-235>238-100500-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
200 PM CDT SAT JUN 9 2001

...HEAVY RAIN REDEVELOPING OVER THE REGION...

...REMNANTS OF ALLISON MOVING SOUTHEAST AND EMERGING OVER THE GULF...

A VERY SERIOUS AND LIFE THREATENING FLOOD EVENT CONTINUES TO UNFOLD
OVER SOUTHEAST TEXAS. THE CENTER OF CIRCULATION ASSOCIATED WITH
FORMER TROPICAL STORM ALLISON IS NEAR PALACIOS TEXAS. THIS CENTER OF
CIRCULATION IS DRIFTING EAST AT 5 MPH AND WILL LIKELY RE-EMERGE OVER
THE WESTERN GULF BY EARLY EVENING. IF THIS OCCURS...IT IS POSSIBLE
THAT THE TROPICAL PREDICTION CENTER WILL BEGIN RE-ISSUING ADVISORIES
ON ALLISON. THERE IS SOME POTENTIAL FOR ALLISON TO BE DEFINED AS A
TROPICAL DEPRESSION THIS EVENING AND POSSIBLY BE UPGRADED TO A
TROPICAL STORM.

WINDS WILL BECOME EAST LATER THIS AFTERNOON AND SURFACE WINDS ARE
FORECAST TO INCREASE AS THE SURFACE PRESSURE GRADIENT INCREASES.
THIS WILL RAISE TIDES SLIGHTLY BUT MORE IMPORTANTLY IT WILL BLOCK
DRAINAGE OF AREA RIVER BASINS. A COASTAL FLOOD WATCH MAY BE REQUIRED
THIS EVENING.

IT DOES APPEAR THAT HEAVY RAIN WILL AGAIN REDEVELOP CLOSE TO THE
CIRCULATION CENTER OVERNIGHT. SINCE THIS FEATURE IS FURTHER SOUTH...IT
APPEARS THAT THE HEAVIEST RAIN WILL FOCUS FURTHER SOUTH IN BRAZORIA...
MATAGORDA...SOUTHERN FORT BEND...GALVESTON...WHARTON AND CHAMBERS
COUNTIES. AT THIS TIME IT APPEARS THAT AREAS SOUTH OF U.S. HIGHWAY 59
WILL RECEIVE 3 TO 5 INCHES OF RAIN WITH MANY LOCATIONS RECEIVING 10 TO
15 INCHES OF RAIN OVERNIGHT. ANOTHER 20 INCH RAINFALL REPORT WOULD NOT
BE A BIG SURPRISE. AREAS THAT RECEIVED EXCESSIVE RAINFALL LAST NIGHT
WILL ALSO RECEIVE RAIN BUT THE HEAVIEST RAIN SHOULD FOCUS CLOSER TO
THE COAST.

THIS CAN NOT BE STRESSED ENOUGH...IF YOU DO NOT NEED TO TRAVEL PLEASE
DONT ROADS ARE STILL CLOGGED WITH ABANDONED VEHICLES AND MANY
ROADS...FEEDER ROADS AND LOW WATER CROSSINGS ARE STILL FLOODED. ANY
ADDITIONAL RAINFALL WILL COMPLICATE AN ALREADY DIFFICULT...DANGEROUS
AND LIFE THREATENING SITUATION.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 8, 7:55 PM CDTFlash Flood WarningHGXHarris4 hr
Jun 8, 8:05 PM CDTFlash Flood WarningHGXBrazoria, Fort Bend3 hr
Jun 8, 9:22 PM CDTFlash Flood WarningHGXWashington3 hr
Jun 8, 10:00 PM CDTFlash Flood WarningHGXMontgomery4 hr
Jun 8, 11:00 PM CDTFlash Flood WarningHGXFort Bend2 hr
Jun 8, 11:57 PM CDTFlash Flood WarningHGXHarris3 hr
Jun 9, 12:47 AM CDTFlash Flood WarningHGXBrazoria, Fort Bend6 hr
Jun 9, 1:19 AM CDTFlash Flood WarningHGXGrimes, Waller, Washington6 hr
Jun 9, 1:30 AM CDTFlash Flood WarningHGXGalveston5 hr
Jun 9, 1:50 AM CDTFlash Flood WarningHGXMontgomery5 hr
Jun 9, 2:50 AM CDTFlash Flood WarningHGXHarris6 hr
Jun 9, 6:23 AM CDTFlash Flood WarningHGXGalveston2 hr
Jun 9, 6:36 AM CDTFlash Flood WarningHGXBrazoria, Fort Bend3 hr
Jun 9, 7:01 AM CDTFlash Flood WarningHGXMontgomery3 hr
Jun 9, 8:44 AM CDTFlash Flood WarningHGXGalveston2 hr
Jun 9, 8:50 AM CDTFlash Flood WarningHGXHarris, Montgomery6 hr
Jun 9, 12:34 PM CDTFlash Flood WarningHGXBrazoria, Fort Bend3 hr
Jun 9, 12:40 PM CDTFlash Flood WarningHGXLiberty3 hr
Jun 9, 1:08 PM CDTFlash Flood WarningHGXChambers, Galveston3 hr
Jun 9, 4:09 PM CDTFlash Flood WarningHGXChambers, Galveston111 min
Jun 9, 6:00 PM CDTFlash Flood WarningHGXChambers, Galveston, Harris3 hr

Nearby

Flash Flood Warnings in Texas, 2001Every flash flood warning in 2001

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.