Alert archive / Texas / Flash Flood Warnings in 2001

Flash Flood Warning 74, NWS Houston/Galveston, TX

September 1, 2001Jackson County, Matagorda County, Wharton County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Sep 1, 2001, 6:40 AM CDT for Jackson County, Matagorda County, Wharton 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: Sep 1, 2001, 6:40 AM CDT (11:40 UTC)
Expired: Sep 1, 2001, 9:30 AM CDT
In force: 3 hr
Issued by: NWS Houston/Galveston, TX
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Jackson County, TX, Matagorda County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 126 km from the middle of the area, began a volume at 11:43 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

Corpus Christi, TX (KCRP), launched 00:00Z, 11.7 hours before the alert went out and 181 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: 2099 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 567 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 125 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.4

Open this sounding in Storm Lab

The text

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

000 
WGUS54 KHGX 011139
FFWHOU
TXC239-321-481-011430-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
640 AM CDT SAT SEP 1 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  JACKSON COUNTY IN SOUTHEAST TEXAS
  WHARTON COUNTY IN SOUTHEAST TEXAS
  MATAGORDA COUNTY IN SOUTHEAST TEXAS

* UNTIL 930 AM CDT

* AT 635 AM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING  
VERY HEAVY RAINFALL FROM EDNA IN JACKSON COUNTY EASTWARD ALONG AND 
SOUTH OF U.S. HIGHWAY 59 TO WHARTON. THE THUNDERSTORMS WERE MOVING 
NORTHEAST AT 25 MPH. RAINFALL RATES OF UP TO TWO INCHES PER HOUR 
WERE INDICATED BY RADAR.  RADAR ALSO INDICATED 2 TO 4 INCHES OF RAIN 
HAD FALLEN IN THE SAME AREA SINCE 3 AM.  AN ADDITION ONE OR TWO 
INCHES OF RAINFALL IS EXPECTED BY 830 AM.

* FLOODING OF ROADWAYS AND STREAMS IS EXPECTED IN THE SOUTHEAST 
PORTION OF JACKSON COUNTY...WHARTON COUNTY ALONG AND SOUTH OF U.S. 
59...AND NORTHWEST MATAGORDA COUNTY MAINLY WEST OF THE COLORADO 
RIVER AND NORTH OF HIGHWAY 35.
  
SMALL CREEKS...STREAMS...BAYOUS..AND FARM-TO-MARKET OR OTHER 
SECONDARY ROADS MAY FLOOD QUICKLY. AVOID LOCATIONS WHERE 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 2922 9611 2883 9611 2883 9655 2922 9655

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 Sep 1, 2:40 AM CDT, 4 hours earlier.

Area forecast discussion, Sep 1, 2:40 AM CDT, 4 hours before

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
240 AM CDT SAT SEP 01 2001

CONVECTION INCREASING SINCE MIDNIGHT ALONG THE COAST. COASTAL
SURFACE TROUGH SERVING AS FOCUS WITH AT LEAST SOME SUPPORT FROM
UPPER LEVEL DISTURBANCE APPROACHING FROM WEST. SYNOPTIC FEATURES
HAVE WEAKENED SOME LAST 24H AND MESOSCALE SYSTEMS ARE MAIN DRIVERS.
ETA AND AVN BOTH SHOW AXIS OF 2.25 PWATS REMAINING OVER SOUTHEAST
TEXAS THROUGH TODAY WITH MID TO UPPER FLOW WEST TO EAST AND LOW
LEVEL FLOW SOUTH TO SOUTHWEST.  UNFORTUNATELY IDEAL SET UP FOR
TRAINING CONVECTION. EXPECT EXCESSIVE RAINFALL WHERE THE TRAINING
SETS UP.  WILL GO WITH SCATTERED 1 TO 2 INCHES NORTH...SCATTERED 2
TO 4 INCH RAINS ISOLATED 5 TO 8 INCHES SOUTH.  IF CONVECTION GETS
MORE FOCUSSED AND..OR LASTS LONGER THESE AMOUNTS ARE TOO
CONSERVATIVE. EXPECT HIGHER CHANCE OF EXCESSIVE RAIN SOUTHERN HALF
ASSUMING SURFACE FOCUS STAYS NEAR COAST. HOWEVER...GIVEN SATURATED
SOILS ALL AREAS AND FLOODING ALREADY IN PROGRESS...WILL EXTEND FFA
THROUGH TODAY ALL AREAS.

MODELS TRY TO GIVE US A CHANCE...REPEAT CHANCE... OF A BREAK SUNDAY
AND MONDAY AS MID TO UPPER TROF AXIS PROGGED JUST TO OUR EAST. STILL
KEEP AMPLE MOISTURE SO SCATTERED CONVECTION STILL IN THE PICTURE.
ALSO...MODELS COULD BE OFF A BIT. AVN NOW RETROGRADES MID LEVEL TROF
TUESDAY AND WEDNESDAY SETTING THE STAGE FOR MORE ORGANIZED HEAVY
RAIN AGAIN BY MID WEEK.  SINCE THIS IS A CHANGE FROM PREVIOUS MODEL
RUNS WILL STAY WITH CHANCE CATEGORY FOR NOW IN EXTENDED.

30/43/39

.HGX...FFA ALL CWA TODAY.
       SCEC 0-60 NM HIGH ISLAND TO THE MATAGORDA SHIP CHANNEL.

CLL...TT 082/073 089/073 089 865
IAH...TT 080/075 087/075 088 +75
GLS...TT 083/079 086/079 087 +85

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 8:36 AM CDT	Flash Flood Warning	HGX	Fort Bend	3 hr
Sep 1, 9:06 AM CDT	Flash Flood Warning	HGX	Harris	114 min
Sep 1, 9:52 AM CDT	Flash Flood Warning	HGX	Galveston	2 hr

Nearby

Flash Flood Warnings in Texas, 2001 Every 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.