FXUS64 KHGX 100522
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1122 PM CST WED DEC 9 2009
.AVIATION...
SCT/BKN CIRRUS CLOUDS CONTINUE TO OVERSPREAD THE AREA. THIS WILL PERSIST
THROUGH THE REST OF THE NIGHT AND THROUGHOUT THE DAY TOMORROW AS NORTH
WINDS 5 TO 12 KNOTS INLAND AND 15 TO 20 KNOTS AND GUSTY ALONG THE COAST
GRADUALLY VEER TO THE NORTHEAST. SOME SCT/BKN LOWER CLOUDS (BETWEEN
5000 AND 10000 FEET) COME INTO THE PICTURE TOMORROW NIGHT...AND EXPECT
DECKS TO LOWER TOWARD MVFR LEVELS ALONG WITH AN INCREASING CHANCE OF
-RA/-SHRA DURING THE DAY ON FRIDAY. 42
&&
.PREV DISCUSSION... /ISSUED 939 PM CST WED DEC 9 2009/
UPDATE...
CURRENT INTERIOR DEW POINTS IN THE LOW TO MID 20S...LOW TO MID
30S NEAR COAST. THIS IS THE ONE MAIN POSITIVE IN FORECASTING SUB
FREEZING THURSDAY MINIMUM TEMPS ACROSS THE NORTHERN 2/3RDS OF THE
FA. GENERALLY COMMUNITIES ALONG AND NORTH OF THE I-10 CORRIDOR WILL
EXPERIENCE A FEW HOURS OF UPPER 20S TO LOWER 30S AROUND SUNRISE.
THE INHIBITING FACTORS OF A DENSE HIGH CANOPY AND SLOWLY VEERING
NORTHERLY WINDS BETWEEN 5 TO 10 KNOTS MAY KEEP MANY INLAND LOCALES
IN THE LOWER 30S VERSUS THE UPPER 20S...OR THIS INSULATION/MIXING
MAY ADD 5 OR 6 DEGREES ON CURRENT NUMBERS. BETTING DRY AIR AND
OCCASIONAL STRATO CI BREAKS SHOULD BE ENOUGH TO KEEP THIS FROM
BEING A MIN TEMP BUST.
NORTHEASTERLY WINDS WILL REINFORCE THIS DRIER AIR MASS BROUGHT IN
BEHIND THIS MORNING'S FROPA. THUS...AS WAS THE CASE TODAY...EXPECT
AFTERNOON MAXIMUMS TO STRUGGLE TO GET INTO THE LOWER 50S BY MID DAY.
MOST OF THE DAY SPENT IN THE MID TO UPPER 40S MAKES FOR A CHILLED
THURSDAY UNDER PARTLY BECOMING MOSTLY CLOUDY SKIES BY EARLY FRIDAY.
S-SW MID LEVEL WINDS TRANSPORTING GULF MOISTURE FURTHER INLAND ATOP
A COOL DOME WILL KICK IN MORE EFFICIENT ISENTROPIC LIFT FRIDAY...SOUTHERN
COUNTY RAIN CHANCES (SHRA) INCREASE TO LIKELY BY EARLY FRIDAY AFTERNOON
UNDER THIS UPGLIDE PATTERN. 31
PREV DISCUSSION... /ISSUED 341 PM CST WED DEC 9 2009/
DISCUSSION...
DRY AIR FILTERING INTO THE AREA BEHIND THIS MORNINGS COLD FRONT
WITH DEWPOINT TEMPERATURES HAVING DROPPED INTO THE 20S THIS
AFTERNOON ACROSS ALL BUT THE IMMEDIATE COASTAL AREAS. HAVE KEPT
TEMPERATURES IN THE 30S ACROSS MOST OF THE AREA WITH UPPER 20S
ALONG THE NORTHERN PERIPHERY OF THE CWA. LOW TEMPS TONIGHT COULD
BE SLIGHTLY COOLER THAN FORECAST BUT FEEL THAT WITH THE SFC HIGH
SO FAR TO OUR NORTH WINDS WILL NOT GO CALM OVERNIGHT AND HIGH
CLOUD COVER WILL ALSO ACT TO LIMIT COOLING A BIT. TEMPS WILL STILL
BE CHILLY...WITH MOST AREAS NORTH OF THE US 59 CORRIDOR SEEING
TEMPS AT OR BELOW FREEZING AT LEAST BRIEFLY OVERNIGHT.
UPPER LEVEL FLOW REMAINS RELATIVELY ZONAL THROUGH THE WEEKEND.
MAIN FORECAST CONCERN WILL BE THE DEVELOPMENT OF ANOTHER COASTAL
LOW EARLY ON FRIDAY. WILL KEEP LIKELY POPS GOING ALONG THE COAST AS
ISENTROPIC UPGLIDE SHOULD RESULT IN GOOD COVERAGE OF SHOWERS
DURING THE DAY ON FRIDAY. HAVE EXTENDED CHANCE POPS INTO SATURDAY FOR
AREAS ALONG THE COAST. IN ADDITION TO THE RAINFALL THIS
DISTURBANCE ALSO HAS THE POTENTIAL TO PRODUCE SOME MINOR COASTAL
FLOODING DURING HIGH TIDE ON FRIDAY.
AFTER A RELATIVELY WARM WEEKEND BOTH THE GFS AND ECMWF ARE
ADVERTISING ANOTHER COLD FRONT MOVING THROUGH THE AREA EARLY NEXT
WEEK. WILL KEEP CHANCE POPS IN THE FORECAST FOR MONDAY WITH COOLER
TEMPERATURES TUESDAY AND WEDNESDAY BEHIND THE FRONT. 38
MARINE...
COLD FRONT CLEARED THE WATERS THIS MORNING WITH MODERATE TO STRONG
NORTHERLY WINDS IN ITS WAKE. EXPECT WINDS TO VEER FROM NORTH TO
NORTHEAST BY THURSDAY AS THE SURFACE HIGH MOVES TOWARDS THE
SOUTHEASTERN STATES. WINDS WILL REMAIN 20-25 KTS OVER THE OFFSHORE
WATERS. MAY SEE A BRIEF LULL IN THE WINDS THU AFTN BUT THEY WILL
PICK UP AGAIN THU EVENING AND REMAIN ELEVATED THROUGH FRIDAY AS SFC
LOW DEVELOPS OVER THE WESTERN GULF. TO KEEP THINGS SIMPLE...WILL
EXTEND SCA FOR THE 00-60 NM WATERS THROUGH 00Z SATURDAY. WILL HAVE A
SCEC FOR THE BAYS THROUGH 18Z THURSDAY WHERE 15-20 KT WINDS ARE
EXPECTED. SWELLS WILL BEGIN TO DEVELOP THU NIGHT DUE TO THE LONG
FETCH OF EASTERLY WINDS. SEAS WILL BUILD TO 8-10 FT OVER THE
OFFSHORE WATERS. WINDS WILL GRADUALLY DIMINISH FRI NIGHT/SATURDAY AS
THE LOW PUSHES EAST OF THE AREA. GENERALLY LIGHT WINDS ARE EXPECTED
SATURDAY THROUGH MONDAY (5-15 KTS)...WITH ONSHORE FLOW RETURNING
SUNDAY. COASTAL FLOODING DOES NOT APPEAR TO BE AS SIGNIFICANT OF A
THREAT WITH THIS SYSTEM AS WITH THE LAST FEW. THE SFC LOW IS NOT
FORECAST TO BE AS STRONG (GENERALLY AROUND 1014 MB). THE
EXTRATROPICAL STORM SURGE MODEL IS ONLY FORECASTING TIDES ABOUT 1 TO
1.3 FEET ABOVE NORMAL...WHICH RESULTS IN PEAK LEVELS AROUND 3 FT AT
PLEASURE PIER. WILL MONITOR THE NEXT COUPLE MODEL RUNS BUT MAY BE
ABLE TO GO WITHOUT A WATCH THIS TIME. 35
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 29 52 37 53 45 / 0 10 20 40 40
HOUSTON (IAH) 32 53 39 54 47 / 0 10 20 60 40
GALVESTON (GLS) 39 54 50 58 53 / 0 10 40 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH THURSDAY MORNING FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CST FRIDAY FOR THE FOLLOWING
ZONES: 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...31
AVIATION/MARINE...42
