Alert archive / Texas / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 63, NWS Houston/Galveston, TX

May 2, 2007Houston County, Trinity County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at May 2, 2007, 11:22 PM CDT for Houston County, Trinity County, Texas. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 2, 2007, 11:22 PM CDT (04:22 UTC)
Expired
May 3, 2007, 12:00 AM CDT
In force
38 min
Issued by
NWS Houston/Galveston, TX
Area
Counties, with a storm outline in the text

Counties Houston County, TX, Trinity County, TX

The radar

The Houston radar (KHGX), 193 km from the middle of the area, began a volume at 04:24 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 2, 7:59 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 4.4 hours before the alert went out and 202 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 00:00Z on 2007-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1137 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 00:00Z on 2007-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
1137 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1161 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
170 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.8

Open this sounding in Storm Lab

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 2, 8:07 PM CDT, 3 hours 15 minutes earlier.

Area forecast discussion, May 2, 8:07 PM CDT, 3 hours 15 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
807 PM CDT WED MAY 2 2007

.DISCUSSION...
STRONG MCS EVOLVING OVER CENTRAL TX AND BEARING DOWN ON THE CWA.
BASED ON CURRENT MOVEMENT STORMS WILL BEGIN MOVING INTO THE CWA
BETWEEN 9 AND 11 PM. DAMAGING WINDS WILL BE THE MAIN THREAT GIVEN
THE FAST MOVEMENT AND BOW STRUCTURES SEEN WITHIN THE MCS. LARGE
HAIL AND ISOLATED TORNADOES ALSO POSSIBLE. SPC HAS ISSUED TORNADO
WATCH #214 FOR THE NW THIRD OF THE CWA UNTIL 08Z. HAVE BOOSTED UP
POPS AND HAVE MENTION OF SEVERE/HEAVY RAIN FOR ENTIRE CWA TONIGHT.
WILL KEEP AN EYE ON TRENDS AND MAY INCREASE POPS SOME MORE OVER SE
ZONES IF MCS PROGRESSES. HAVE HELD OFF ON ISSUING A FLOOD WATCH
FOR THE TIME BEING GIVEN THE FAST MOVEMENT OF THE STORMS.

&&

.PREV DISCUSSION... /ISSUED 231 PM CDT WED MAY 2 2007/

DISCUSSION...
A RATHER CHALLENGING FORECAST FOR TONIGHT AND THURSDAY. ANOTHER
MCS IS TRACKING ACROSS CENTRAL TEXAS. THE CURRENT TRAJECTORY WILL
BRING THE MCS ACROSS SOUTHEAST TEXAS LATE TONIGHT AND EARLY
THURSDAY. UPPER LEVEL WINDS ARE PROGGED TO BECOME STRONGLY
DIVERGENT OVERNIGHT AS THE UPPER TROUGH OVER WEST TEXAS PUSHES
EAST. PWS ARE FORECAST TO CLIMB BETWEEN 1.6 AND 1.9 INCHES AND
THE STRONG CAP OVER THE AREA WILL ERODE AS COOLER 500 MB TEMPS
ASSOCIATED WITH THE TROUGH MOVE EAST. STRONG SHEAR AND CAPE
SUGGEST SOME POTENTIAL FOR STRONG TO SEVERE STORMS. PRIMARY THREAT
WILL BE WIND DAMAGE AND LARGE HAIL. HAVE MENTIONED SEVERE IN THE
WESTERN ZONES 00-06Z AND AREAWIDE 06-12Z. HIGH PW AIR AND STRONG
DIVERGENT UPPER LEVEL WINDS ALSO SUGGEST A GOOD POTENTIAL FOR
HEAVY RAIN. SPEEDY STORM MOTIONS SHOULD KEEP RAINFALL MOVING SO
EXCESSIVE RAIN POSSIBLE BUT NOT LIKELY.

MESO-SCALE BOUNDARIES HAVE A WAY OF ALTERING FORECASTS QUICKLY.
AT THIS TIME...DO NOT HAVE A GREAT FEEL OF WHETHER OR NOT THE COLD
POOL WILL BE EAST OF HERE BY THURSDAY AFTERNOON OR WHETHER AN
OUTFLOW BOUNDARY WILL FOCUS ADDITIONAL PRECIPITATION EAST OF HERE
OR RIGHT OVER THE AREA. SINCE GUIDANCE IS IN GOOD AGREEMENT...
OPTED TO PLAY IT SAFE AND ACCEPT THE CURRENT SOLUTION OF HIGH
POPS. SPC HAS THE AREA OUTLOOKED FOR SEVERE STORMS. WILL NOT
MENTION SEVERE FOR THURSDAY AT THIS TIME DUE TO ABUNDANT
UNCERTAINTY.

WILL MAINTAIN SLT CHC POPS FOR FRIDAY AS A WEAK S/WV MOVES ACROSS
THE REGION. A 500 MB RIDGE WILL AMPLIFY OVER THE WEEKEND BUT SE TX
LIES BETWEEN THE BUILDING RIDGE AND UPPER LEVEL TROUGH. UPPER
LEVELS WINDS ARE PROGGED TO REMAIN SOUTHWEST AND A SERIES OF
DISTURBANCES WILL MOVE ACROSS SE TX. HAVE TRIMMED A FEW DEGREES
FROM GUIDANCE DUE TO EXPECTED CLOUDS AND AN OCCASIONAL SHOWER.

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      68  82  68  88  70 /  90  70  10  10  10
HOUSTON (IAH)              70  83  69  89  70 /  70  70  10  20  10
GALVESTON (GLS)            73  80  73  83  73 /  60  70  20  20  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

DISCUSSION...35
Hazardous weather outlook, May 2, 8:31 PM CDT, 2 hours 51 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
831 PM CDT WED MAY 2 2007

TXZ163-164-176>179-195>200-210>214-226-227-235>238-031215-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-
GALVESTON-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-
WHARTON-
831 PM CDT WED MAY 2 2007

...ISOLATED SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAINFALL
EXPECTED DURING THE OVERNIGHT HOURS...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TONIGHT

A COMPLEX OF STRONG TO SEVERE THUNDERSTORMS OVER CENTRAL TEXAS
WILL MOVE INTO SOUTHEAST TEXAS DURING THE OVERNIGHT HOURS TONIGHT.
THE STORMS ARE EXPECTING TO BEGIN MOVING INTO THE FAR NORTHERN AND
WESTERN PORTIONS OF SOUTHEAST TEXAS BETWEEN 9 AND 11 PM...AND
SPREAD ACROSS THE REST OF THE AREA DURING THE LATE NIGHT PERIOD. A
FEW OF THE STORMS WILL LIKELY BECOME SEVERE...WITH DAMAGING
STRAIGHT LINE WINDS BEING THE MAIN THREAT. HAIL AND ISOLATED
TORNADOES ARE ALSO POSSIBLE.

SOME OF THE STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL. BY
THURSDAY MORNING...RAINFALL AMOUNTS WILL AVERAGE 1 TO 2 INCHES
WITH ISOLATED TOTALS OF UP TO 4 INCHES POSSIBLE. FLOODING OF
STREETS...FEEDER ROADS...UNDERPASSES...AND LOW WATER CROSSINGS
WILL BE POSSIBLE. MOTORIST SHOULD USE CAUTION WHILE DRIVING
TONIGHT. NEVER DRIVE INTO AN AREA WHERE WATER COVERS THE ROAD.

.DAY TWO...THURSDAY

ADDITIONAL THUNDERSTORMS WILL DEVELOP ON THURSDAY AS AN UPPER LOW
INTERACTS WITH A MOIST AND UNSTABLE AIRMASS IN PLACE. A FEW OF
THESE STORMS WILL HAVE THE POTENTIAL TO BECOME SEVERE...PRODUCING
LARGE HAIL AND DAMAGING DOWNBURST WINDS. IN ADDITION...LOCALLY
HEAVY RAINFALL WILL BE POSSIBLE.

.DAYS THREE THROUGH SEVEN...FRIDAY THROUGH TUESDAY

.SPOTTER INFORMATION STATEMENT...

EMERGENCY MANAGEMENT AND SPOTTER ACTIVATION IS LIKELY TONIGHT
INTO EARLY THURSDAY.

In the hours before

Local storm report, May 2, 10:43 PM CDT, 39 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1043 PM CDT WED MAY 02 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1005 PM     TSTM WND DMG     COLLEGE STATION         30.60N 96.31W
05/02/2007                   BRAZOS             TX   LAW ENFORCEMENT

            TREES DOWN ON LANGFORD STREET IN COLLEGE STATION

1010 PM     TSTM WND DMG     7 SW NORMANGEE          30.96N 96.20W
05/02/2007                   MADISON            TX   LAW ENFORCEMENT

            TREE DOWN ON OSR AT FM 1452 IN THE NORTHWEST CORNER OF
            THE COUNTY

&&

MORELAND

The office that day

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

IssuedProductOfficeCountiesLasted
May 2, 9:33 PM CDTSevere Thunderstorm WarningHGXBrazos, Burleson42 min
May 2, 10:06 PM CDTSevere Thunderstorm WarningHGXMadison39 min
May 2, 10:16 PM CDTSevere Thunderstorm WarningHGXBrazos, Grimes44 min
May 2, 10:43 PM CDTSevere Thunderstorm WarningHGXHouston47 min
May 2, 11:41 PM CDTSevere Thunderstorm WarningHGXPolk64 min
May 3, 3:37 AM CDTFlash Flood WarningHGXHarris53 min
May 3, 3:52 AM CDTFlash Flood WarningHGXChambers68 min
May 3, 3:50 PM CDTSevere Thunderstorm WarningHGXLiberty25 min
May 3, 4:20 PM CDTSevere Thunderstorm WarningHGXHarris41 min
May 3, 4:31 PM CDTSevere Thunderstorm WarningHGXMontgomery44 min
May 3, 4:39 PM CDTSevere Thunderstorm WarningHGXPolk51 min
May 3, 4:42 PM CDTTornado WarningHGXPolk48 min
May 3, 4:49 PM CDTTornado WarningHGXMontgomery41 min
May 3, 5:03 PM CDTSevere Thunderstorm WarningHGXPolk42 min
May 3, 5:16 PM CDTSevere Thunderstorm WarningHGXPolk, San Jacinto, Trinity23 min
May 3, 5:26 PM CDTTornado WarningHGXHarris, Liberty, Montgomery49 min
May 3, 5:42 PM CDTSevere Thunderstorm WarningHGXPolk14 min
May 3, 6:11 PM CDTSevere Thunderstorm WarningHGXHarris49 min
May 3, 6:14 PM CDTSevere Thunderstorm WarningHGXLiberty, Montgomery46 min
May 3, 6:51 PM CDTFlash Flood WarningHGXHarris, Liberty69 min

Nearby

Severe Thunderstorm Warnings in Texas, 2007Every severe thunderstorm warning in 2007

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.