Alert archive / Texas / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 73, NWS Houston/Galveston, TX

May 21, 2001Harris County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at May 21, 2001, 2:46 PM CDT for Harris County, Texas. It was in force for 59 min. 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: May 21, 2001, 2:46 PM CDT (19:46 UTC)
Expired: May 21, 2001, 3:45 PM CDT
In force: 59 min
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), 39 km from the middle of the area, began a volume at 19:50 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, 7.8 hours before the alert went out and 191 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: 1654 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 653 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 118 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 4.3

Open this sounding in Storm Lab

The text

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

000 
WUUS54 KHGX 211947
SVRHOU
TXC201-212045-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
246 PM CDT MON MAY 21 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 345 PM CDT

* AT 240 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 2   
MILES WEST OF CLOVERLEAF...MOVING EAST AT 15 MPH.

* LOCATIONS IN THE PATH OF THE SEVERE THUNDERSTORM INCLUDE...
  JACINTO CITY...GALENA PARK...I-10/I-610 EAST
  CLOVERLEAF
  CHANNELVIEW...SHELDON
  HIGHLANDS
  BARRETT...CROSBY
  BAYTOWN

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 2984 9531 2973 9531 2972 9498 2984 9495
          2992 9503

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 May 21, 2:36 PM CDT, 10 minutes earlier.

Area forecast discussion, May 21, 2:36 PM CDT, 10 minutes before

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
236 PM CDT MON MAY 21 2001

COLD FRONT APPROACHING A LUFKIN TO HUNTSVILLE TO BRENHAM LINE AS OF
19Z. AREA HAS ESCAPED SEVERE THUNDERSTORMS SO FAR THIS AFTERNOON...
POSSIBLY DUE TO STABILIZING GRAVITY TYPE WAVES SEEN SURGING SOUTHWARD
THROUGH SOUTHEAST TEXAS THIS MORNING. SEVERE THUNDERSTORM WATCH IS
IN EFFECT FOR COUNTIES JUST TO OUR EAST. COLD FRONT STILL HAS TO
TRACK THROUGH THE REST OF SOUTHEAST TEXAS THIS AFTERNOON AND EARLY
THIS EVENING...SO WILL RETAIN 40% POPS AND KEEP THE MENTION OF
SEVERE FOR THE IAH AND GLS GROUPS UNTIL THE FRONT CLEARS THE AREA
THIS EVENING.

AFTER THE FRONT SWEEPS THROUGH TONIGHT...WE'LL SEE CLEARING SKIES
AND COOLER TEMPERATURES (WACO IS DOWN TO 68 DEGREES...AND THIS IS
AROUND 8 DEGREES BELOW FORECASTED MOS/MAV GUIDANCE). WILL CALL FOR
LOWS A DEGREE OR TWO UNDER GUIDANCE FOR BOTH TUESDAY AND WEDNESDAY
MORNINGS WHICH IS STILL CLOSE TO RECORD LOW READINGS. POSITION OF
DEEP EASTERN U.S. CUTOFF LOW WILL ALLOW FOR COOL NIGHTS AND
SEASONABLY WARM DAYS THROUGH THURSDAY MORNING. COLD FRONT FROM THE
NORTH MAY BE ABLE TO INITIATE SOME CONVECTION ON THURSDAY AND FRIDAY
AS A WEAK RETURN FLOW SETS UP...SO WILL KEEP THE MENTION OF SLIGHT
CHANCE POPS FOR THOSE DAYS. WILL KEEP THE REST OF THE EXTENDED DRY
FOR NOW.

THANKS CRP FOR COORDINATION CALL.

.HGX...SCEC BAYS AND SCA 0-60 NM WATERS FOR TONIGHT.

42/TF

PRELIMS...                     RECORD LOWS FOR TUESDAY.....WEDNESDAY
CLL UB 053/082 054/084 063 -00           CLL - 53/1919.....54/1917
IAH UB 056/082 054/084 064 400           IAH - 59/1976.....55/1967
GRLS UB 063/078 061/081 072 4-0           GLS - 54/1892.....59/1892

In the hours before

Local storm report, May 21, 8:54 AM CDT, 5 hours 52 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
854 AM CDT MON MAY 21 2001

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

1212 AM    CROCKETT                  TX   WIND DAMAGE
05/21/01   HOUSTON                        25 OR MORE TREES DOWN
                                          ON STRUCTURES - ROOF
                                          TORN OFF A WAREHOUSE -
                                          MANY TREES DOWN AND
                                          LIMBS BROKEN OFF IN
                                          OTHER PARTS OF COUNTY.
                                          RErPORTED BY EMERGENCY
                                          MANAGEMENT.

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 10:31 PM CDT	Severe Thunderstorm Warning	HGX	Burleson	29 min
May 20, 11:04 PM CDT	Severe Thunderstorm Warning	HGX	Brazos, Burleson, Grimes	56 min
May 21, 3:58 PM CDT	Severe Thunderstorm Warning	HGX	Chambers, Harris	47 min

Nearby

Severe Thunderstorm Warnings in Texas, 2001 Every severe thunderstorm 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.