FXUS64 KHGX 082138
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
338 PM CST TUE DEC 8 2009
.DISCUSSION...
WIDE RANGE OF TEMPS ACROSS THE CWA TODAY...FROM 75-80 SOUTH OF THE
WARM FRONT TO BARELY 50 NEAR CLL. PREFRONTAL TROF WILL PUSH ACROSS
THE AREA LATE IN THE EVENING FOLLOWED BY A COLD FRONT A COUPLE HOURS
LATER. HIGH DEWPOINTS MOVING OVER THE COOL WATERS WILL ALLOW SEA
FOG (SOME DENSE) TO PERSIST UNTIL THE PREFRONTAL TROF AND/OR COLD
FRONT PUSHES THRU LATER TONIGHT. HIGH PRES WILL BUILD IN IN ITS
WAKE PROVING DRY AND COOL WX THRU THURS (BUT THERE MAY BE SOME
PERIODS OF BKN CIRRUS MOVING OVERHEAD). LONG FETCH OF MODERATE/STRONG
ERLY WINDS SETS UP ACROSS THE NRN GULF THUR & FRI AS THE HIGH
PUSHES EAST AND COASTAL TROF/LOW SETS UP ALONG THE LOWER/MID TX
COAST. TIDES WILL PROBABLY BE ELEVATED AND WILL CONTINUE TO
MONITOR FOR POSSIBLE ADVSY, ETC. MODELS SUGGESTING THE COASTAL LOW
MOVING NEWD OFF THE UPPER COAST THURS NIGHT & FRI BRINGING THE
NEXT SHOT OF PRECIP...ESP SRN 2/3 OF THE CWA. GET A BIT OF DRIER
AIR BACKDOOR INTO THE AREA IN ITS WAKE SAT & SUN WITH HIGH PRES
BUILDING DOWN THE MIDWEST AND ERN STATES. ONSHORE FLOW INCREASES
MON AHEAD OF THE NEXT FRONT PENCILED IN FOR MON NIGHT/TUE. THIS
COULD BE A COLDER FRONT THAN MEX GUIDANCE SUGGESTS WITH A
1030-1040 HIGH PUSHING IN BEHIND IT. WENT BELOW GUIDANCE
TEMPS...BUT WILL NEED TO BE LOWERED FURTHER IF MODEL CONSISTENCY
PERSISTS. 47
&&
.MARINE...
TRICKY FORECAST FOR TONIGHT. SEA FOG WAS MOVING ONSHORE AT MID
AFTERNOON AND WILL LIKELY OVERSPREAD THE BAYS BEFORE SUNSET. A
PREFRONTAL BOUNDARY WILL MOVE THROUGH THE AREA AROUND MIDNIGHT AND
MAY HELP TO LIFT THE FOG. HOWEVER...IT WILL LIKELY LIFT BETWEEN 3 AM
AND 6 AM WHEN THE COLD FRONT MOVES THROUGH THE BAYS AND OFF THE
COAST.
AFTER THE FRONT MOVES OFFSHORE...EXPECT NEAR SCA CONDITIONS BY
WEDNESDAY AFTERNOON AS MODERATE NORTHEASTERLY WINDS DEVELOP. THESE
CONDITIONS WILL PERSIST INTO FRIDAY AS HIGH PRESSURE TO THE NORTH
INTERACTS WITH LOWER PRESSURE TO OUR SOUTH. THE WINDS LOOK TO
FINALLY RELAX AROUND FRIDAY AFTERNOON. WITH THE LONG FETCH OF
MODERATE TO STRONG EASTERLY WINDS OVER THE NORTHERN GULF...TIDAL
PROBLEMS MAY RESULT ALONG THE IMMEDIATE COAST...THE BOLIVAR
PENINSULA...AND BARRIER ISLANDS THURSDAY AND FRIDAY. 40
&&
.1144 AM AVIATION...
THE MODELS HAVE BEEN A BIT ERRATIC AND HAVE NOT VERIFIED VERY
WELL FOR CEILINGS AND VISIBILITY OVER THE PAST FEW RUNS. THE
CURRENT SITUATION HAS A FRONTAL BOUNDARY ENTERING INTO THE KCLL
AREA. THERE IS ALSO A SLOW MOVING WARM FRONT RIGHT AT THE COAST
NEAR KLBX AND KGLS. THE NAM12 MODEL AT THE SURFACE WAS ACTUALLY
DOING A GOOD JOB OF DEPICTING THE MOVEMENTS OF BOTH FEATURES AND
A DECENT JOB IN THE VERY SHORT TERM FOR CEILINGS AND VISIBILITY.
IF THE SITUATION EVOLVES AS THE NAM12 INDICATES...THE AREA OF
LIFR/IFR CONDITIONS WILL PUSH EAST-NORTHEASTWARD AS BOTH FRONTS
ADVANCE. EXPECT THAT AS THE DRIER AIR FILTERS INTO THE FORECAST
AREA...THE TERMINAL SITES WILL SEE IMPROVEMENT. SOMETIME AROUND
AND AFTER 21Z...MOST SITES SHOULD EITHER EXPERIENCE MVFR OR EVEN
VFR CEILINGS.
THE MODELS ARE THEN FORECASTING ANOTHER BOUT OF MVFR TO IFR
CONDITIONS TONIGHT. FROM THE METRO HOUSTON AIRPORTS SOUTHEAST TO
ALONG THE COAST LIFR CONDITIONS MAY EVEN RETURN. FEEL THAT THIS
SCENARIO IS ACTUALLY PLAUSIBLE GIVEN THAT ANOTHER FRONTAL SYSTEM
WILL PUSH THROUGH THE AREA LATE TONIGHT BETWEEN 09Z AND 14Z. VFR
CONDITIONS ARE EXPECTED TO DEVELOP BEHIND THIS FRONT.
SINCE THE TIMING AND LEVEL OF THE EVENTS ARE A BIT SHAKY...THE
CONFIDENCE LEVEL IN THE FIRST 12 TO 18 HOURS OF THE FORECAST IS
MEDIUM AT BEST. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 41 53 32 53 43 / 10 0 0 0 20
HOUSTON (IAH) 48 57 35 55 45 / 10 0 0 0 30
GALVESTON (GLS) 52 58 44 56 52 / 10 0 0 0 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...JACKSON...
MATAGORDA.
GM...DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 5 PM CST THIS
AFTERNOON FOR THE FOLLOWING ZONES: 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.
&&
$$
DISCUSSION...30
