Alert archive / Texas / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 87, NWS Houston/Galveston, TX

August 15, 2002Harris County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Aug 15, 2002, 8:47 AM CDT for Harris County, Texas. It was in force for 34 hr. 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, 8:47 AM CDT (13:47 UTC)
Expired
Aug 16, 2002, 6:30 PM CDT
In force
34 hr
Issued by
NWS Houston/Galveston, TX
Area
Counties, with a storm outline in the text

County Harris County, TX

The radar

The Shreveport radar (KSHV), 189 km from the middle of the area, began a volume at 13:48 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 severe thunderstorm 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

Shreveport, LA (KSHV), launched 12:00Z, 1.8 hours before the alert went out and 198 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, Shreveport, LA at 12:00Z on 2002-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 930 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, Shreveport, LA at 12:00Z on 2002-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.19395878Sfc1 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
930 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
679 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
38 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.

794 
WUUS54 KHGX 151347
SVRHOU
TXC201-151415-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
845 AM CDT THU AUG 15 2002

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  HARRIS COUNTY IN SOUTHEAST TEXAS

* UNTIL 915 AM CDT

* AT 845 AM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER
  SOUTH HOUSTON...MOVING EAST AT 25 MPH.

* LOCATIONS IN THE PATH OF THE SEVERE THUNDERSTORM INCLUDE...
  PASADENA...SOUTH HOUSTON...ELLINGTON FIELD
  DEER PARK...CLOVERLEAF...BAYTOWN
  SAN JACINTO STATE PARK...LA PORTE...SHOREACRES

MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR
BUSINESS. STAY AWAY FROM WINDOWS

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

LAT...LON 2977 9535 2956 9526 2961 9495 2994 9504

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Aug 15, 2:50 AM CDT, 5 hours 57 minutes earlier.

Area forecast discussion, Aug 15, 2:50 AM CDT, 5 hours 57 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, 3 hours 47 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, 2 hours 40 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, 2 hours 37 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.

IssuedProductOfficeCountiesLasted
Aug 15, 1:55 AM CDTSpecial Marine WarningHGX2 hr
Aug 15, 3:47 AM CDTFlash Flood WarningHGXBrazoria, Galveston118 min
Aug 15, 4:00 AM CDTSpecial Marine WarningHGX2 hr
Aug 15, 4:33 AM CDTSevere Thunderstorm WarningHGXGalveston5 hr
Aug 15, 5:48 AM CDTFlash Flood WarningHGXBrazoria, Galveston2 hr
Aug 15, 7:28 AM CDTSpecial Marine WarningHGX62 min
Aug 15, 7:43 AM CDTFlash Flood WarningHGXGalveston107 min
Aug 15, 8:22 AM CDTSpecial Marine WarningHGX53 min
Aug 15, 9:13 AM CDTSpecial Marine WarningHGX2 hr
Aug 15, 10:26 AM CDTFlash Flood WarningHGXHarris3 hr
Aug 15, 10:34 AM CDTFlash Flood WarningHGXGrimes, Waller, Washington3 hr
Aug 15, 11:10 AM CDTFlash Flood WarningHGXBrazoria, Galveston3 hr
Aug 15, 11:13 AM CDTSpecial Marine WarningHGX2 hr
Aug 15, 11:37 AM CDTTornado WarningHGXGalveston23 min
Aug 15, 11:59 AM CDTTornado WarningHGXGalveston31 min
Aug 15, 1:14 PM CDTFlash Flood WarningHGXGrimes, Waller, Washington3 hr
Aug 15, 1:19 PM CDTSpecial Marine WarningHGX116 min
Aug 15, 1:45 PM CDTFlash Flood WarningHGXBrazoria, Galveston, Harris3 hr
Aug 15, 3:47 PM CDTFlash Flood WarningHGXWaller, Washington2 hr
Aug 15, 3:55 PM CDTFlash Flood WarningHGXHarris3 hr
Aug 15, 4:51 PM CDTFlash Flood WarningHGXBrazoria, Galveston3 hr
Aug 15, 6:10 PM CDTSpecial Marine WarningHGX2 hr
Aug 15, 6:10 PM CDTSpecial Marine WarningHGX2 hr

Nearby

Severe Thunderstorm Warnings in Texas, 2002Every severe thunderstorm 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.