Severe Thunderstorm Warning 15, NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
415 AM CDT WED MAR 14 2007

.DISCUSSION...
MESO-SCALE CONVECTIVE SYSTEM HAS MOVED OVER UPPER TEXAS COAST AND
WATERS. BOW ECHOES HAS BEEN PRODUCING STRONG WINDS WHILE TRAVERSING
MARINE REGION. MUCH OF INLAND AREAS HAS STABILIZED WITH RAIN COOLED
AIR. UPPER LOW NOW PROGRESSIVELY MOVING EAST AND PROGGED BY MODELS
TO MOVE OVER OUR REGION THIS AFTERNOON. MODEL SOUNDINGS INDICATE
WET BULB ZERO LOWERING BELOW 10 KFT DURING THIS PERIOD AND LAPSE RATES
BECOMING QUITE STEEP BY MID DAY. AS PER SWODY1 ELEVATED CONVECTION
THAT START DURING MORNING SHOULD BECOME SURFACED BASED DURING AFTERNOON.
WE MENTIONED POSSIBLE SEVERE STORMS FOR THIS AFTERNOON. IMPROVING CONDITIONS
WEST TO EAST THIS EVENING AS UPPER TROUGH LINE STARTS TO MOVE EAST
OF CWFA. DECREASING CLOUD COVER WITH MOIST GROUND AND RELATIVELY
LIGHT WINDS WILL RESULT IN PATCHY FOG LATER TONIGHT. UPPER LOW
WILL BE EAST OF THE REGION THURSDAY WITH A RATHER WEAK PRESSURE
GRADIENT OVER OUR CWFA. COLD FRONT WILL APPROACH NORTHERN PORTIONS
OF CWFA EARLY FRIDAY AND RAPIDLY MOVE SOUTH ACROSS REGION. SOME INCREASE
IN PW VALUES INDICATED BY MODELS INCREASING TO NEAR 1.3 INCHES
VICINITY FRONT. GFS INDICATE WEAK DIVERGENT FIELD ALOFT NEAR BASE
OF UPPER TROUGH FRIDAY. VERTICAL PROFILES INDICATE ENOUGH
INSTABILITY FOR CONVECTION. WE SHALL CONTINUE WITH SLIGHT CHANCE
POPS FRIDAY AND THIS SHOULD BE MAINLY NEAR FRONTAL BOUNDARY.
COOLING AND DRYING FRIDAY NIGHT. COMING WEEKEND WILL BE RAIN FREE
WITH SLIGHTLY BELOW NORMAL DAYTIME TEMP VALUES AND OVERNIGHT LOWS
NEAR NORMAL. SURFACE RIDGE WILL SHIFT TO EAST OF REGION LATER IN
THE WEEKEND WITH ONSHORE FLOW RETURNING. WEAK UPPER RIDGE OVER
REGION WILL GRADUALLY FLATTEN WHILE SHIFTING MORE TO THE EAST
EARLY NEXT WEEK. IT WILL START TO MOISTEN UP AS ONSHORE FLOW
DEEPENS BY THE MIDDLE OF NEXT WEEK.
37

&&

.MARINE...
5 TO 10 KNOT WINDS FROM THE EAST THROUGH THE SOUTH PREVAIL ACROSS
THE COASTAL WATERS EARLY THIS MORNING. THE WIND FIELD CONTINUES TO
RECOVER FROM YESTERDAYS STORMS. FOR THE FORECAST...WILL SHOW 2 TO 3
FOOT SEAS NEARSHORE AND GENERALLY 4 TO 6 FOOT SEAS OFFSHORE (CAUTION
FLAGS ARE IN EFFECT THIS MORNING FOR THE 20-60 NM WATERS). WINDS AND
SEAS/BAY WATERS WILL OF COURSE BE HIGHER IN AND NEAR SHOWERS AND
THUNDERSTORMS THAT ARE EXPECTED TO RETURN TO THE AREA EITHER LATER
THIS MORNING OR THIS AFTERNOON. A STRONGER AND MORE ORGANIZED STORM
COMPLEX IS EXPECTED TO MOVE EASTWARD ACROSS THE AREA LATER TONIGHT
AND EARLY WEDNESDAY MORNING AS THE UPPER LOW OUT WEST GETS CLOSER TO
THE AREA. 42

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      73  56  81  56  66 /  40  20  10  10  20
HOUSTON (IAH)              71  57  79  59  70 /  50  30  10  10  20
GALVESTON (GLS)            72  62  77  63  70 /  50  30  10  10  20

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
456 AM CDT WED MAR 14 2007

TXZ163-164-176>179-195>200-210>214-226-227-235>238-151100-
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-
456 AM CDT WED MAR 14 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT
A STRONG UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE OVER OUR REGION
TODAY. THE MOIST AIR MASS WILL BECOME MORE UNSTABLE AS THIS UPPER
LOW MOVES OVERHEAD THIS AFTERNOON. SOME OF THE STORMS THAT DEVELOP
MAY BECOME SEVERE THIS AFTERNOON. THE MAIN THREAT WILL BE LARGE
HAIL AND DAMAGING WINDS. EXPECT IMPROVING CONDITIONS THIS EVENING
AS THE STORM SYSTEM START TO MOVE EAST OF OUR REGION.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE THIS AFTERNOON.