Tornado Warning 19, NWS Houston/Galveston, TX

000 
WWUS54 KHGX 071952
SVSHGX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
251 PM CDT THU JUL 7 2005

TXC321-072015-
/O.CON.KHGX.TO.W.0019.000000T0000Z-050707T2015Z/
MATAGORDA-
251 PM CDT THU JUL 7 2005

...A TORNADO WARNING CONTINUES FOR MATAGORDA COUNTY UNTIL 315 PM
CDT...

AT 249 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO AS WELL AS STRONG WINDS 
AND HAIL.  THIS STORM WAS LOCATED NEAR MARKHAM...MOVING WEST AT 20 
MPH.

* LOCATIONS IMPACTED INCLUDE...
  MARKHAM...

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 2897 9621 2879 9618 2880 9575 2901 9589

$$

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1242 PM CDT THU JUL 7 2005

.UPDATE...
.AVIATION...SEVERAL CONCERNS THIS AFTERNOON. THINK CIGS WILL STAY
VFR FOR THE MOST PART. ETA DID NOT INITIALIZE WELL SO HAVE LEANED
TOWARD THE GFS...PROBLEM IS THE GFS GENERATES A LARGE MCS OVER THE
NORTHWESTERN ZONES AROUND 06Z. RUC AND TO A LESSER EXTENT THE ETA
LEND SOME SUPPORT TO THE GFS SOLN SO HAVE KEPT A PROB 30 FOR CLL
TAF. WILL KEEP LATE AFT/EVENING TSRA IN THE TAFS FOR IAH/HOU AS
NUMEROUS BOUNDARIES INTERACT. CLOUD COVER HAS LIMITED HEATING AND
THIS MAY LIMIT CONVECTIVE POTENTIAL. OUTFLOW BOUNDARIES WREAKING
HAVOC WITH WINDS BUT HAVE LEANED TOWARD SE WINDS REDEVELOPING. 43

LOOKS LIKE ANOTHER NORTH TEXAS MCS HEADED IN OUR GENERAL DIRECTION
THIS MORNING. EARLY MORNING SURFACE OBSERVATIONS CONTINUE TO SHOW
A VERY MOIST AIR MASS AHEAD OF THE SYSTEM AND VISIBLE IMAGERY
INDICATES PARTLY CLOUDY SKIES. THIS AREA SHOULD HEAT UP QUICKLY
THIS MORNING AND MIX OUT SOME OF THIS LOW LEVEL MOISTURE...AND WE
ARE LIKELY TO SEE INVERTED-V THERMODYNAMIC PROFILES ACROSS THE
INLAND REGIONS. WILL LOWER THE DEWPOINTS SLIGHTLY ACROSS THE
NORTHERN PARTS OF THE AREA TO ACCOUNT FOR MIXING. THIS WILL ALSO
LOWER THE HEAT INDEX VALUES SLIGHTLY TO BELOW ADVISORY CRITERIA.
THE COASTAL COUNTIES MAY HAVE A DIFFICULT TIME HEATING UP TO
ADVISORY CRITERIA DUE TO CLOUDS. HOWEVER...WE WONT GIVE UP ON
THEM JUST YET. WILL LEAVE THE HEAT ADVISORY IN PLACE JUST IN CASE
THE CLOUDS CLEAR OUT ENOUGH. DESPITE THE CLOUDS...THE 15Z
OBSERVATION AT GALVESTON SHOWS A HEAT INDEX OF 98...AND AT BAY
CITY 102.

THE ONLY OTHER CHANGES IN THE ZONES WILL BE TO UP THE POPS TO
CHANCE AREAWIDE AND TO MENTION SEVERE IN ALL BUT THE COASTAL
ZONES. 46

&&

.PREV DISCUSSION... (ISSUED 507 AM CDT THU JUL 7 2005)

DISCUSSION...
CURRENTLY...LARGE CLUSTER OF STORMS SPEWING OUT OF THE MOUTH OF THE
SABINE RIVER. FAIRLY STOUT WINDS COMPARED TO THE LAST FEW NIGHTS
PUMPING MOISTURE INTO THIS SYSTEM. ALSO LEADING TO MID 70 DEWPOINTS
RISING OVER THE COASTAL COUNTIES. REMAINS OF THE STATIONARY FRONT
DRAPED ACROSS THE REGION FROM AROUND WACO TO HUNTSVILLE TO JASPER.

AS THE FLOW WEAKENS A LITTLE IN THE WAKE OF THIS SYSTEMS DEPARTURE
WILL PROBABLY SEE MOISTURE POOL OVER THE AREA (ESPECIALLY NEAR THE
BOUNDARY) WHICH COMBINED WITH THE ABUNDANT INSOLATION SHOULD MAKE
FOR A HOT AND HUMID AFTERNOON. HEAT INDICES OF 103 TO 105 SHOULD
BE COMMON THIS AFTERNOON...THE SOUTHWESTERN 1/2 OF THE AREA COULD
SEE SOME 108 VALUES AND ALONG THE COAST COULD GET A FEW 110 DEGREE
READINGS...AND AFTER YESTERDAYS RECORD TEMPERATURES AND HIGH HEAT
INDICES WILL CONTINUE THE HEAT ADVISORY FOR THE COASTAL COUNTIES
THROUGH 7 PM. WITH MORE MIXING OCCURRING INLAND WILL PROBABLY ONLY
GET THE PEAK HEAT INDICES FOR AN HOUR OR TWO. MODIFIED ETA BUFR
SOUNDINGS SUPPORT STRONG GUSTY WINDS WITH ANY STORMS THAT FORM
BUT THINK THAT SPEEDS SHOULD BE LESS THAN 45 MPH DUE TO LESS
EVAPORATIVE COOLING...COURTESY OF THE HIGHER DEWPOINTS. MIGHT GET
CLOSE TO RECORDS AGAIN THIS AFTERNOON. NAM/GFS DO PROG ANOTHER
SHORT WAVE TO DROP SOUTH ALONG EASTERN PERIPHERY OF THE WESTERN
RIDGE AND MAY AGAIN ENHANCE RAIN CHANCES LATE THIS AFTERNOON OR
EVENING. HAVE PARED BACK POPS A LITTLE OVER THE COURSE OF THE
NEXT FEW DAYS. STRONGER VORT MAX DROPS SOUTH LATE SATURDAY BUT
IT MAY BE TOO FAR WEST.

HURRICANE DENNIS BEARING DOWN ON JAMAICA AND STILL FORECAST TO MOVE
INTO THE EASTERN GULF SATURDAY THEN ON TOWARD THE MOBILE BAY AREA
SUNDAY AFTERNOON. SWELLS FROM DENNIS MAY LEAD TO GREATER RUNUP ON
LOCAL BEACHES SATURDAY-MONDAY. OTHERWISE UNLESS MAJOR CHANGES OCCUR
THEN DENNISS REACH BE LIMITED TO AREAS EAST OF HERE. WILL STILL
CARRY CHANCE POPS MONDAY IN THE EAST SHOULD IT VEER A LITTLE FARTHER
WEST. DENNIS FORECAST TO TRACK NORTHWEST AFTER LANDFALL AND MAY
BRING SOME BETTER RAIN CHANCES TO THE EASTERN AREAS EARLY NEXT WEEK
WITH MOISTURE TRANSPORT GETTING STRONGER WITH THE SAME OR WARMER
AFTERNOON TEMPERATURES EXPECTED...AHH SUMMER

45

AVIATION...
VFR EXCEPT IN/NEAR ANY ISO TSRA. WEAK BOUNDARY STILL REMAINS IN
PLACE JUST N OF THE METRO AREA. UNTIL IT GRADUALLY WASHES OUT LATER
THIS EVENING IT COULD BE A FOCUS FOR PRECIP THRU THE PERIOD. LIKE
YDAY...FCST AFTERNOON SOUNDINGS DO SUPPORT DOWNBURSTS IN THE
STRONGER STORMS. PLANNING TO LEAVE MENTION OF PRECIP OUT OF THE 12Z
TAFS AND AMEND IF IT BECOMES NECESSARY. DIFFICULT WIND FCST ON TAP
AGAIN DUE TO WEAK PRESSURE GRADIENT IN PLACE. ONGOING TREND ALREADY
IN TAFS LOOK OK FOR NOW.  47

MARINE...
SWELLS ASSOCIATED FROM HURRICANE DENNIS SHOULD BEGIN REACHING THE
UPPER TEXAS COAST SUNDAY AFTERNOON...PEAKING SUN NIGHT AND
MONDAY...THEN DIMINISHING MONDAY NIGHT. SCA FLAGS LOOK LIKELY FOR AT
LEAST THE 20-60NM GROUP BY SUN NIGHT. ALL OF THIS OF COURSE IS
SUBJECT TO CHANGE DEPENDING ON THE EVENTUAL TRACK...SPEED AND
INTENSITY OF THE HURRICANE.  47

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...
HEAT ADVISORY FROM UNTIL 7 PM THURSDAY FOR THE FOLLOWING ZONES...
      BRAZORIA...CHAMBERS...GALVESTON...JACKSON...AND MATAGORDA.
.GM...NONE.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
630 AM CDT THU JUL 7 2005

GMZ330-335-TXZ163-164-176>179-195>200-210>214-226-227-235>238-080300-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-GALVESTON-
GALVESTON BAY-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MATAGORDA BAY-MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-
WASHINGTON-WHARTON-
630 AM CDT THU JUL 7 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT.

...HEAT ADVISORY IS IN EFFECT FOR THE COASTAL COUNTIES TIL 7 PM...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
TODAY. A FEW STORM THIS AFTERNOON DURING PEAK HEATING MAY BE STRONG
ENOUGH PRODUCE MICROBURST WINDS 30 TO 45 MPH BUT SHOULD BE VERY
ISOLATED IN NATURE. RAINFALL TOTALS OF 1 TO 2 INCHES WILL BE POSSIBLE
IN THESE STRONGER STORMS.

IN ADDITION...A HEAT ADVISORY IS IN EFFECT FOR THE COASTAL
COUNTIES OF BRAZORIA...CHAMBERS...GALVESTON...JACKSON...AND MATAGORDA
THROUGH 7 PM. NEAR RECORD HIGH TEMPERATURES COMBINED WITH HIGH
RELATIVE HUMIDITY VALUES WILL CREATE HEAT INDEX VALUES OF 105 TO 111
DEGREES ACROSS THE ADVISORY AREA.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
NO HAZARDOUS WEATHER IS ANTICIPATED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.