Tornado Warning 47, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1030 AM CDT THU JUL 22 2004

.DISCUSSION...
12Z UPPER ANALYSIS SHOW LOW PRESSURE OVER SE TX. UPPER LEVEL WINDS
ARE BROADLY DIVERGENT. 850 WINDS ARE BROADLY DIVERGENT AND THE SEA
BREEZE IS PROVIDING ENOUGH LOW LEVEL CONVERGENCE TO FIRE STORMS NEAR
THE COAST. THERMAL PROFILES INDICATE CAPPING WILL NOT BE A HINDRANCE
THIS AFTERNOON. PWS ARE BETWEEN 1.7 AND 1.9 INCHES AND CONVECTIVE
TEMPS ARE BETWEEN 84 AND 86 DEGREES. STORM MOTION WILL BE AROUND 10
MPH SO SOME LOCALLY HEAVY RAINFALL IS POSSIBLE...MAINLY EAST OF US
HIGHWAY 59. HAVE ALREADY SEEN 2 TO 3 INCHES IN MATAGORDA AND JACKSON
COUNTIES THIS MORNING. WILL UPDATE THE HWO TO INCLUDE MENTION OF
HEAVY RAIN. 43/46

&&

PREVIOUS: BOUNDARY APPROX 60NM OFFSHORE WILL MOVE ONSHORE IN THE 11Z
- 14Z TIME FRAME WHICH WILL TOUCH OFF COASTAL COUNTY SHOWERS.
EXPECTING WIDESPREAD COVERAGE BY EARLY AFTERNOON AS ATMOSPHERE
BECOMES MORE UNSTABLE. INCREASING PWATS WITH CONVECTIVE TEMPS IN THE
UPPER 80S FORTIFYING THE FACT THAT MOST IN THE CWA WILL EXPERIENCE
SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE PM HOURS. MESOETA
SOUNDING PROGS ALSO DISPLAY A MINOR VEERING OF WINDS FROM 18Z TO 0Z
AND...WITH YESTERDAYS REPORTS OF FUNNELS IN NW HARRIS COUNTY ON THE
BRAIN...I WILL MENTION THAT THE POTENTIAL FOR SOME OF THESE
THUNDERSTORMS TO EXHIBIT ROTATION DOES EXIST. 700 MB FLOW IS SW SO
HAVE UPPED 18Z TO 0Z POPS TO 60 MAINLY FROM A BAY CITY TO HOUSTON TO
LAKE LIVINGSTON LINE IN RESPONSE. IN REVIEW...MY POPS ARE BASED ON
50% AREAL COVERAGE AND 80% GONNA HAPPEN...WORKS OUT TO AN
ACROSS-THE-BOARD 40%ER DAY FOR OUR CWA.

RIDGING RETURNS FROM THE EAST TOMORROW WITH THE MAIN THEMES BEING
THOSE AFTERNOON SEABREEZE POPPERS AND SLIGHTLY ABOVE NORMAL MAXIMUMS
ON SATURDAY PER A MORE WESTERLY COMPONENT TO THOSE SOUTHERLY WINDS.
CONFIDENCE DWINDLES QUICKLY FROM SUNDAY NIGHT ONWARD AS EXTENDED MODELS
DEPICT ANOTHER JULY FRONT TO SWEEP THROUGH MONDAY NIGHT INTO
TUESDAY. RARE TO SEE TWO JULY FRONTS SO WILL BACK OFF ON THE
ECMWF/MRF SOLUTION OF DEEP TROUGHINESS OVER THE MS RIVER VALLEY...OR
A SECOND JULY FRONT AFFECTING OUR CWA NEXT WEEK. HAVE TAPERED GRIDS
TO REFLECT A 30% POPS SUN THRU TUES JUST IN CASE THE SECOND FRONT DOES
DROP.

&&

MARINE: FORECASTING WIND DIRECTION WILL BE A PICK EM THIS WEEKEND
THRU EARLY NEXT WEEK. SURFACE HIGH SHOULD BE OVERHEAD FOR MOST OF
THE WEEKEND. SUN/MON DEPENDS ON HOW CLOSE THE WEAK COOL FRONT GETS
ALONG WITH THE EVENTUAL TRACK OF THE WAVE IN THE CARIBBEAN...BOTH OF
WHICH FCST CONFIDENCE IS LOW AT THIS POINT.

AVIATION: MOISTURE LEVELS FCST TO BE HIGHER THAN YDAY. THIS...THE
SEABREEZE AND PROGGED CONVECTIVE TEMPS AROUND 87 SHOULD LEAD TO
GREATER AREAL COVERAGE OF PRECIP THAN WE SAW YDAY...ESP ACROSS THE
SOUTHERN 2/3 OF SE TX. LOCALLY HEAVY DOWNPOURS AND GUSTY WINDS
POSSIBLE IN THE STRONGER STORMS.

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

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)  91 73 94 72 94 / 40 10 20 05 20
HOUSTON(IAH)           91 75 95 73 96 / 60 20 20 05 20
GALVESTON (GLS)        88 80 89 79 91 / 60 20 20 05 20

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1100 AM CDT THU JUL 22 2004

TXZ163-164-176>179-195>200-210>214-226-227-235>238-222300-
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-
1100 AM CDT THU JUL 22 2004

.DAY ONE...TODAY AND TONIGHT.
...LOCALLY HEAVY RAIN POSSIBLE THIS AFTERNOON...
...FUNNEL CLOUDS POSSIBLE THIS AFTERNOON...

SHOWERS AND THUNDERSTORMS WILL REDEVELOP THIS AFTERNOON OVER MUCH
OF THE AREA. THE ATMOSPHERIC ENVIRONMENT FAVORS THE DEVELOPMENT OF
SHORT LIVED FUNNEL CLOUDS. THESE FUNNEL CLOUDS OCCASIONALLY
EXTEND TO THE GROUND AND BECOME SHORT LIVED AND WEAK TORNADOES. THEY
CAN PRODUCE MINOR DAMAGE IF IN CONTACT WITH THE GROUND. KEEP AN EYE TO
THE SKY THIS AFTERNOON.

MID LEVEL WINDS ARE RELATIVELY WEAK...SO ANY STORMS THAT DEVELOP WILL
MOVE SLOWLY. SLOW MOVING STORMS WILL PRODUCE LOCALLY HEAVY RAIN.
WIDESPREAD RAINFALL OF A HALF INCH IS EXPECTED WITH LOCALIZED
HEAVIER RAINFALL TOTALS OF 2 TO 4 INCHES POSSIBLE IN THE STRONGER
STORMS. URBAN STREET FLOODING IS THE PRIMARY HAZARDOUS WEATHER
THREAT.

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

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED LATER THIS AFTERNOON.