Alert archive / Texas / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 55, NWS Houston/Galveston, TX

April 25, 2015Colorado County, Fort Bend County, Wharton County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Apr 25, 2015, 9:37 AM CDT for Colorado County, Fort Bend County, Wharton 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: Apr 25, 2015, 9:37 AM CDT (14:37 UTC)
Expired: Apr 25, 2015, 10:15 AM CDT
In force: 38 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon

Counties Colorado County, TX, Fort Bend County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 106 km from the middle of the area, began a volume at 14:37 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.

Issued	Product	Office	Lasted
Apr 25, 3:09 AM CDT	Severe Thunderstorm Watch	SPC	7 hr
Apr 25, 7:12 AM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 2.6 hours before the alert went out and 225 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: 2734 J/kg
Mixed-layer CIN: -147 J/kg
Mixed-layer LCL: 652 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 130 m²/s²
0-3 km storm-relative helicity: 187 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

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 Apr 25, 6:33 AM CDT, 3 hours 4 minutes earlier.

Area forecast discussion, Apr 25, 6:33 AM CDT, 3 hours 4 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
633 AM CDT SAT APR 25 2015

.DISCUSSION...
SEE THE MARINE AND THE 12Z AVIATION DISCUSSION BELOW.

40

&&

.AVIATION...
THUNDERSTORMS ARE THE MAIN HAZARD THROUGH ABOUT 15Z THIS MORNING.
ISOLATED STRONG STORMS ARE POSSIBLE AND ADDED 25 KNOT GUSTS FOR
THUNDERSTORMS TO KCXO...KIAH...AND KHOU. OTHER THREATS WILL BE
LOCALLY HEAVY RAINFALL AND HAIL.

VFR CONDITIONS WILL THEN DEVELOP BY MIDDAY AND PERSIST THROUGH
EARLY EVENING. MVFR CONDITIONS DUE MAINLY TO FOG ARE EXPECTED BY
LATE EVENING THROUGH THE OVERNIGHT. THERE IS A CHANCE THAT IFR
CONDITIONS WILL DEVELOP.

40

&&

.MARINE...
THUNDERSTORMS MAY AFFECT THE MARINE AREAS THROUGH THE LATE MORNING
PERIOD. SUNDAY MAY SEE A BREAK...HOWEVER CAN NOT RULE OUT ISOLATED
SHOWERS AND THUNDERSTORMS. THUNDERSTORMS MAY BECOME MORE
WIDESPREAD MONDAY AHEAD OF THE NEXT COLD FRONT. MODERATE TO STRONG
OFFSHORE WINDS BEHIND THE FRONTAL PASSAGE EARLY TUESDAY MAY LEAD
TO ADVISORY CONDITIONS TUESDAY AND WEDNESDAY.

40

&&

.PREV DISCUSSION... /ISSUED 423 AM CDT SAT APR 25 2015/

DISCUSSION...
THUNDERSTORMS CONTINUE TO FIRE ALONG AN OUTFLOW BOUNDARY THAT
EXTENDS FROM ABOUT CALDWELL TO HONDO TO SOUTH OF DEL RIO. SOME OF
THE STORMS ARE PRODUCING LARGE HAIL AND A FEW OF THESE STORMS WILL
LIKELY HOLD TOGETHER AND APPROACH SE TX LATER THIS MORNING. SEVERE
THUNDERSTORM WATCH 107 HAS BEEN ISSUED THROUGH 10 AM FOR THE
WESTERN EDGE OF SE TX. SE TX LIES IN A 125-130 KNOT RRQ AND THIS
WILL ENHANCE LIFT THROUGH THE MORNING AND THE LATEST SHORT TERM
GUIDANCE SUPPORTS AN EXPANDING AREA OF SHRA/TSRA ACROSS MAINLY
THE CENTRAL/COASTAL COUNTIES THROUGH NOON. STILL EXPECTING SOME
PARTIAL CLEARING FROM WEST TO EAST DURING THE AFTERNOON. HIGH
TEMPS TODAY ARE STRONGLY DEPENDENT ON IF/WHEN SKIES CLEAR AND HOW
WET THE GROUND BECOMES. PARTIAL CLEARING TONIGHT WITH WET GROUNDS
SHOULD YIELD AT LEAST PATCHY FOG ON SUNDAY MORNING. MIN TEMPS WILL
AGAIN BE UNSEASONABLY WARM.

ON SUNDAY...THE FLOW ALOFT REMAINS SW AND STRONG PVA WILL MOVE
ACROSS THE AREA IN THE AFTN. CAN'T RULE OUT GETTING A FEW
SHRA/TSRA SO WILL MAINTAIN 20 POPS. THINGS DETERIORATE QUICKLY
SUNDAY NIGHT INTO MONDAY. AN UPPER LEVEL LOW WILL DROP INTO THE
TEXAS PANHANDLE SUNDAY NIGHT AND TRACK EASTWARD ALONG THE RED
RIVER THROUGH TUESDAY NIGHT. SE TX WILL LIE IN A 95 KT LFQ ON
MONDAY AFTN WITH CAPE VALUES AOA 2900. LI VALUES ARE PROGGED TO
FALL TO -10 AND HELICITY VALUES WILL INCREASE TO BETWEEN 200-300.
FCST SOUNDINGS BECOME SATURATED WITH PW VALUES EXCEEDING 2.00
INCHES. CURRENTLY THE FCST SOUNDINGS SHOW WEAK CAPPING ON MON
MORNING IN THE 850-700 MB LAYER SO WILL HAVE TO SEE IF THE CAP
ACTUALLY ERODES AS FCST. DYNAMICS ARE IMPRESSIVE SO AT THIS
TIME...FEEL THE CAP WILL ERODE. MONDAY WILL LIKELY BE AN ACTIVE
WEATHER DAY.

A STRONG COLD FRONT WILL CROSS SE TX EARLY TUESDAY WITH MUCH
COOLER TEMPS DEVELOPING. STILL A BIT UNSTABLE ON TUESDAY IN THE
WAKE OF THE FRONT SO WILL CONT TO MENTION SHRAS IN THE WAKE OF THE
FRONT. MIN TEMPS FOR NEXT WEEK WILL FALL INTO THE 50S WITH SFC DEW
PTS IN THE 40S AND HIGH TEMPS WILL ONLY WARM INTO THE LOWER 70S
TUE-THU.

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      87  69  87  69  81 /  40  10  20  40  60
HOUSTON (IAH)              88  70  88  71  81 /  60  10  20  30  60
GALVESTON (GLS)            81  74  79  72  79 /  60  10  20  20  50

&&

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

DISCUSSION...43
AVIATION/MARINE...40

Hazardous weather outlook, Apr 25, 4:59 AM CDT, 4 hours 38 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
459 AM CDT SAT APR 25 2015

TXZ163-164-176>179-195>200-210>214-226-227-235>238-261000-
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-
459 AM CDT SAT APR 25 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

A WEAK BOUNDARY COUPLED WITH A STRONG UPPER LEVEL DISTURBANCE WILL
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO SOUTHEAST TEXAS
THIS MORNING. SOME OF THE STORMS COULD BE SEVERE WITH LARGE HAIL
AND DAMAGING WINDS. A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR
THE WESTERN EDGE OF SOUTHEAST TEXAS THROUGH 10 AM THIS MORNING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

ANOTHER EPISODE OF SIGNIFICANT WEATHER IS EXPECTED ON MONDAY AS AN
UPPER LEVEL LOW MOVES INTO NORTH TEXAS. THE POTENTIAL EXISTS FOR
LARGE HAIL...DAMAGING WINDS AND ISOLATED TORNADOES. MOISTURE
LEVELS ARE ALSO VERY HIGH SO MINOR FLOODING ISSUES FROM LOCALLY
HEAVY RAIN WILL ALSO BE A POSSIBILITY.

.SPOTTER INFORMATION STATEMENT...

EMERGENCY MANAGERS AND STORM SPOTTERS SHOULD PREPARE FOR
ACTIVATION.

GMZ330-335-350-355-370-375-261000-
GALVESTON BAY-MATAGORDA BAY-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM-
WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM-
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM-
459 AM CDT SAT APR 25 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS COULD AFFECT
PORTIONS OF GALVESTON BAY AND THE ADJACENT COASTAL WATERS THIS
MORNING. A FEW OF THE STORMS COULD PRODUCE GUSTY WINDS AND
DANGEROUS CLOUD TO WATER LIGHTNING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A VIGOROUS UPPER LEVEL STORM SYSTEM WILL BRING SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS TO THE REGION ON MONDAY. A FEW
OF THE STORMS WILL PRODUCE GUSTY WINDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE REQUIRED.

In the hours before

Special weather statement, Apr 25, 8:09 AM CDT, 1 hour 28 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
809 AM CDT SAT APR 25 2015

TXZ213-214-237-238-251400-
BRAZORIA TX-GALVESTON TX-HARRIS TX-CHAMBERS TX-
809 AM CDT SAT APR 25 2015

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BRAZORIA...
SOUTHEASTERN HARRIS...GALVESTON AND CHAMBERS COUNTIES UNTIL 900 AM
CDT...

AT 808 AM CDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM LA PORTE TO NEAR DANBURY...
AND MOVING EAST AT 50 MPH.

WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
SOUTHERN PASADENA...PEARLAND...LEAGUE CITY...SOUTHERN BAYTOWN...
GALVESTON CAUSEWAY...GALVESTON ISLAND WEST END...GALVESTON ISLAND
EAST END...TEXAS CITY...FRIENDSWOOD...LA PORTE...DEER PARK...ALVIN...
NORTHERN ANGLETON...DICKINSON...SOUTH HOUSTON...LA MARQUE...SANTA
FE...SEABROOK...WEBSTER AND HITCHCOCK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

&&

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 PM CDT FOR
SOUTHEASTERN TEXAS.

LAT...LON 2953 9443 2936 9485 2934 9473 2933 9473
      2920 9493 2924 9501 2917 9512 2919 9512
      2921 9520 2918 9515 2914 9530 2923 9557
      2967 9524 2968 9498 2971 9501 2985 9436
      2963 9435
TIME...MOT...LOC 1308Z 259DEG 44KT 2965 9504 2925 9532

!KP!

Local storm report, Apr 25, 8:12 AM CDT, 1 hour 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
812 AM CDT SAT APR 25 2015

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

0808 AM     HAIL             EDNA                    28.97N  96.65W
04/25/2015  M1.00 INCH       JACKSON            TX   LAW ENFORCEMENT

            1 INCH HAIL IN EDNA.

&&

EVENT NUMBER HGX1500136

40

Local storm report, Apr 25, 8:15 AM CDT, 1 hour 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
815 AM CDT SAT APR 25 2015

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

0640 AM     TSTM WND GST     SAN FELIPE              29.80N  96.11W
04/25/2015  M58 MPH          AUSTIN             TX   TRAINED SPOTTER

            MINOR TREE DAMAGE IN SAN FELIPE.

&&

EVENT NUMBER HGX1500137

40

Local storm report, Apr 25, 9:08 AM CDT, 29 minutes before

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Local storm report, Apr 25, 9:09 AM CDT, 28 minutes before

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Special weather statement, Apr 25, 9:31 AM CDT, 6 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 24, 10:40 PM CDT	Special Weather Statement	HGX	Houston	50 min
Apr 25, 1:42 AM CDT	Special Marine Warning	HGX		2 hr
Apr 25, 6:17 AM CDT	Special Weather Statement	HGX	Austin, Waller	43 min
Apr 25, 6:42 AM CDT	Severe Thunderstorm Warning	HGX	Austin, Fort Bend, Harris, Waller	33 min
Apr 25, 7:05 AM CDT	Severe Thunderstorm Warning	HGX	Chambers, Harris, Liberty, Montgomery	40 min
Apr 25, 7:20 AM CDT	Areal Flood Advisory	HGX	Austin, Colorado	115 min
Apr 25, 7:22 AM CDT	Special Weather Statement	HGX	Fort Bend	38 min
Apr 25, 7:36 AM CDT	Severe Thunderstorm Warning	HGX	Austin, Brazoria, Fort Bend, Galveston, Harris, Wharton	24 min
Apr 25, 7:39 AM CDT	Severe Thunderstorm Warning	HGX	Jackson, Matagorda, Wharton	51 min
Apr 25, 7:46 AM CDT	Special Weather Statement	HGX	Liberty	44 min
Apr 25, 7:55 AM CDT	Special Marine Warning	HGX		95 min
Apr 25, 8:07 AM CDT	Areal Flood Advisory	HGX	Chambers, Harris, Liberty	53 min
Apr 25, 8:09 AM CDT	Special Weather Statement	HGX	Chambers, Galveston	51 min
Apr 25, 8:13 AM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Galveston	47 min
Apr 25, 8:16 AM CDT	Special Marine Warning	HGX		59 min
Apr 25, 8:23 AM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Chambers, Galveston, Harris, Matagorda	52 min
Apr 25, 8:27 AM CDT	Areal Flood Advisory	HGX	Brazoria, Matagorda	3 hr
Apr 25, 8:33 AM CDT	Tornado Warning	HGX	Brazoria	27 min
Apr 25, 8:35 AM CDT	Special Marine Warning	HGX		25 min
Apr 25, 8:55 AM CDT	Special Marine Warning	HGX		95 min
Apr 25, 9:18 AM CDT	Special Marine Warning	HGX		87 min
Apr 25, 9:31 AM CDT	Special Weather Statement	HGX	Wharton	44 min
Apr 25, 10:18 AM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Fort Bend, Galveston, Harris	27 min
Apr 25, 10:27 AM CDT	Special Weather Statement	HGX	Fort Bend	33 min
Apr 25, 10:48 AM CDT	Special Marine Warning	HGX		42 min
Apr 25, 10:54 AM CDT	Special Weather Statement	HGX	Brazoria	36 min
Apr 25, 11:20 AM CDT	Special Marine Warning	HGX		55 min
Apr 25, 11:22 AM CDT	Special Weather Statement	HGX	Galveston	38 min
Apr 25, 11:30 AM CDT	Special Marine Warning	HGX		30 min
Apr 25, 12:07 PM CDT	Special Marine Warning	HGX		53 min
Apr 25, 1:02 PM CDT	Special Marine Warning	HGX		13 min

Nearby

Severe Thunderstorm Warnings in Texas, 2015 Every severe thunderstorm warning in 2015

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.