Alert archive / Texas / Flash Flood Warnings in 2002

Flash Flood Warning 14, NWS Houston/Galveston, TX

August 15, 2002Galveston County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Aug 15, 2002, 7:43 AM CDT for Galveston County, Texas. It was in force for 107 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: Aug 15, 2002, 7:43 AM CDT (12:43 UTC)
Expired: Aug 15, 2002, 9:30 AM CDT
In force: 107 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), 24 km from the middle of the area, began a volume at 12:45 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, 0.7 hours before the alert went out and 176 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: 248 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 765 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 88 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 151243
FFWHOU
TXC167-151430-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
740 AM CDT THU AUG 15 2002

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

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

* UNTIL 930 AM CDT

* AT 740 AM CDT...MODERATE TO HEAVY RAINFALL CONTINUES TO TRAIN EAST 
NORTHEAST ACROSS THE COUNTY. RAINFALL RATES HAVE DIMINISHED TO 0.75 
TO 1.25 INCHES PER HOUR BUT SOME LOCATIONS ACROSS SOUTHERN PORTIONS 
OF THE COUNTY HAVE ONGOING STREET AND FEEDER ROAD FLOODING AND THIS 
ADDITIONAL RAIN WILL SUSTAIN THE HIGH WATERS. GALVESTON ISLAND HAS 
BEEN PARTICULARLY HARD HIT OVERNIGHT WITH OVER 6 INCHES OF RAIN AND 
MAJOR STREET FLOODING. 

* FLOODING IS EXPECTED IN OR NEAR...
  TIKI ISLAND...TEXAS CITY...GALVESTON ISLAND

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 2958 9495 2946 9460 2934 9436 2914 9499
          2945 9517

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 Aug 15, 2:50 AM CDT, 4 hours 53 minutes earlier.

Area forecast discussion, Aug 15, 2:50 AM CDT, 4 hours 53 minutes before

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
250 AM CDT THU AUG 15 2002

WIDESPREAD SHWRS AND TSTMS OCCURRING EARLY THIS AM ALONG COASTAL
ZONES AND OFFSHORE EAST OF MID/UPPER LEVEL TROF AXIS WHICH IS
SHIFTING EAST INTO FA.

MAIN FORECAST CONCERN IS 1ST PD POPS AS THERE IS LIKELY TO BE A
DECENT GRADIENT TODAY ACROSS INLAND ZONES. HAVE DECIDED TO TREND
FORECAST WITH A COMPROMISE OF AVN/ETA PRECIP FIELDS. HOWEVER...COULD
MAKE SOME LAST MINUTE ADJUSTMENTS BASED ON RADAR TRENDS LATER THIS
MORN. BELIEVE SHWRS/TSTMS WILL BE ONGOING TO START THE DAY ACROSS
COASTAL ZONES AND PORTIONS OF CENTRAL ZONES. WILL TAPER POPS WITH
EXPECTED PW FIELD WITH 2+ INCHES ACROSS CENTRAL AND COASTAL ZONES
AND LESS THAN 2 INCHES ACROSS N/NW ZONES. WILL ALSO MENTION HEAVY
RAIN IN ALL BUT N/NW ZONES. LIKELY TO SEE AVERAGE AMOUNTS OF 1 TO 2
INCHES WITH ISOLATED 3 TO 5 INCH AMOUNTS ALONG AND SE OF AN EL CAMPO
TO HOUSTON TO CLEVELAND LINE. WILL KEEP LOW CHC POPS FOR 2ND
PERIOD ACROSS THIS AREA...BUT HEAVY RAIN THREAT SHOULD SHIFT NE
OF AREA LATE THIS AFTERNOON AND EVENING.

WILL CONTINUE TO ADVERTISE A DECREASE IN POPS FOR FRIDAY. HOWEVER...
THINK WITH MID-LEVEL WEAKNESS OVER FORECAST AREA WHICH IS SANDWICHED
BETWEEN WEST COAST RIDGE AND BERMUDA HIGH WILL STILL SEE SCT
CONVECTION WITH HEATING FOR ALL BUT N/NW ZONES...SO WILL FORECAST
SLIGHTLY HIGHER THAN GUIDANCE. WILL KEEP CHC ON SAT BUT LOWER TO
SLIGHT CHC ON SUN AS HEIGHTS RISE OVER AREA AND LIKELY TO SEE MORE
SYNOPTIC SCALE SUBSIDENCE FROM RIDGE TO THE WEST.

HIGH TEMPS TODAY AT MOST LOCATIONS SHOULD BE BELOW GUIDANCE NUMBERS
GIVEN EXPECTED PRECIP AND CLOUDS. THE TOUGH AREA WILL BE THE NW
ZONES WHERE SOME HEATING WILL LIKELY OCCUR.

FOR MARINE AREA...WILL KEEP ADVISORY FOR GULF WATERS FOR SEAS AND
HAVE CAUTION MENTIONED FOR BAYS TODAY.

33/47

.HGX....SCA GULF WATERS AND SCEC BAYS

PRELIMS...
CLL EB 092/076 094/075 095 423
IAH TB 088/076 092/076 094 734
GLS TB 086/080 088/080 089 +44
SW COAST                   834

In the hours before

Special weather statement, Aug 15, 5:00 AM CDT, 2 hours 43 minutes before

TXZ178-179-199-200-210>214-226-227-235>238-152100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
500 AM CDT THU AUG 15 2002

...LOCALLY HEAVY RAINFALL THREAT CONTINUES TODAY PRIMARILY
ALONG AND SOUTHEAST OF AN EL CAMPO TO HOUSTON TO CLEVELAND LINE...

NUMEROUS SHOWERS AND THUNDERSTORMS ARE OCCURRING ALONG THE SOUTHEAST
TEXAS COAST EARLY THIS MORNING. PORTIONS OF GALVESTON ISLAND HAVE
RECEIVED OVER 5 INCHES OF RAIN SINCE MIDNIGHT. ADDITIONAL RAINFALL
AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE WITH LOCALIZED AMOUNTS TO 4
OR 5 INCHES OVER THE NEXT 12 HOURS.

BE ALERT FOR HIGH STANDING WATER ON ROADWAYS AND IN LOW LYING AREAS.
MOTORISTS SHOULD REMEMBER NOT TO DRIVE INTO AREAS WHERE WATER COVERS
THE ROADWAY.

A STRONG UPPER LEVEL DISTURBANCE IN CONJUNCTION WITH ABUNDANT GULF
MOISTURE IS PRODUCING THE RAIN. THE DISTURBANCE IS EXPECTED TO
GRADUALLY WEAKEN LATER TONIGHT.

Local storm report, Aug 15, 6:07 AM CDT, 1 hour 36 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
507 AM CST THU AUG 15 2002

TIME(CST)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0455 AM    CRYSTAL BEACH             TX   WIND DAMAGE
08/15/02   GALVESTON                      ROOF BLOWN OFF A HOUSE
                                          AND POWERLINES BLOWN
                                          DOWN. OTHER STRUCTURAL
                                          DAMAGE IN THE AREA.
                                          REPORTED BY EMERGENCY
                                          MANAGEMENT.

Local storm report, Aug 15, 6:10 AM CDT, 1 hour 33 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
610 AM CDT THU AUG 15 2002

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0455 AM    CRYSTAL BEACH             TX   WIND DAMAGE
08/15/02   GALVESTON                      ROOF BLOWN OFF A HOUSE
                                          AND POWERLINES BLOWN
                                          DOWN. OTHER STRUCTURAL
                                          DAMAGE IN THE AREA.
                                          REPORTED BY EMERGENCY
                                          MANAGEMENT.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 15, 1:55 AM CDT	Special Marine Warning	HGX		2 hr
Aug 15, 3:47 AM CDT	Flash Flood Warning	HGX	Brazoria, Galveston	118 min
Aug 15, 4:00 AM CDT	Special Marine Warning	HGX		2 hr
Aug 15, 4:33 AM CDT	Severe Thunderstorm Warning	HGX	Galveston	5 hr
Aug 15, 5:48 AM CDT	Flash Flood Warning	HGX	Brazoria, Galveston	2 hr
Aug 15, 7:28 AM CDT	Special Marine Warning	HGX		62 min
Aug 15, 8:22 AM CDT	Special Marine Warning	HGX		53 min
Aug 15, 8:47 AM CDT	Severe Thunderstorm Warning	HGX	Harris	34 hr
Aug 15, 9:13 AM CDT	Special Marine Warning	HGX		2 hr
Aug 15, 10:26 AM CDT	Flash Flood Warning	HGX	Harris	3 hr
Aug 15, 10:34 AM CDT	Flash Flood Warning	HGX	Grimes, Waller, Washington	3 hr
Aug 15, 11:10 AM CDT	Flash Flood Warning	HGX	Brazoria, Galveston	3 hr
Aug 15, 11:13 AM CDT	Special Marine Warning	HGX		2 hr
Aug 15, 11:37 AM CDT	Tornado Warning	HGX	Galveston	23 min
Aug 15, 11:59 AM CDT	Tornado Warning	HGX	Galveston	31 min
Aug 15, 1:14 PM CDT	Flash Flood Warning	HGX	Grimes, Waller, Washington	3 hr
Aug 15, 1:19 PM CDT	Special Marine Warning	HGX		116 min
Aug 15, 1:45 PM CDT	Flash Flood Warning	HGX	Brazoria, Galveston, Harris	3 hr
Aug 15, 3:47 PM CDT	Flash Flood Warning	HGX	Waller, Washington	2 hr
Aug 15, 3:55 PM CDT	Flash Flood Warning	HGX	Harris	3 hr
Aug 15, 4:51 PM CDT	Flash Flood Warning	HGX	Brazoria, Galveston	3 hr
Aug 15, 6:10 PM CDT	Special Marine Warning	HGX		2 hr
Aug 15, 6:10 PM CDT	Special Marine Warning	HGX		2 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.