FXUS64 KHGX 222150
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
350 PM CST TUE DEC 22 2009
.DISCUSSION...
MID-UPPER TROUGH EVOLVING OVER THE WEST COAST...JET LEVEL SPEED
MAX DEVELOPING ALONG ITS LOWER AXIS...AS WAA KICKS IN AND INCREASES
LL GULF MOISTURE THROUGH EARLY WEDNESDAY. SCATTERED SHOWERS STREAMING
UP AS LOWER LEVELS REACH SATURATION...EXPECT THIS ACTIVITY TO BETTER
FILL IN DURING THE OVERNIGHT HOURS. 25-35 KT LL JET AIDING IN
ADVECTING NEAR-60 DEW POINTS AS FAR NORTH AS CORSICANA THIS
AFTERNOON...MOISTENING UP INTO THE MID 60S/NEAR 1.3 PWAT RANGE BY
THIS TIME TOMORROW. THUS...A VERY MILD EVENING/WED AM IN RELATION
TO PREVIOUS MORNINGS AS OVERCAST AND SHOWERY CONDITIONS KEEP AREA WIDE
AM TEMP MINS IN THE LOWER 60S.
ENSEMBLE ALL AGREE ABOUT BRINGING A NEGATIVELY-TILTED BROAD 5H TROF
UP INTO THE RED RIVER VALLEY TOMORROW AFTERNOON AND TAKING IT
ACROSS THE SOUTHERN PLAINS THROUGH EARLY THURSDAY. NEAR 130 KT 25H
JET NOSING IN FROM WEST TEXAS/TRANS PECOS AS MID-UPPER LEVELS
BECOME INCREASING MORE DIFFULENT THROUGH MIDNIGHT THURSDAY. THE LL
JET WILL ALSO PICK UP TO AROUND 40-50 KTS FROM NORTH OF THE CITY
INTO THE LAKE LIVINGSTON AREA (EXTREME NE FA) FROM AROUND 24/03Z
THROUGH THE EVENTUAL FROPA IN THE 24/06Z-10Z TIME FRAME. ON BOARD
WITH SPC'S THOUGHTS OF SLIGHT RISK FOR SEVERE WEATHER IN THE
OVERNIGHT HOURS...WITH A POSSIBLE QLCS FORMING ACROSS NORTHERN
I-35 CORRIDOR RIGHT AHEAD OF MAIN BOUNDARY...OR ALONG/RIGHT AHEAD
OF A THE COLD FRONT ITSELF. THIS WOULD TAP INTO THE BEST DYNAMICS
FROM ROUGHLY NORTH AND EAST OF A BRENHAM TO HUNTSVILLE TO CORRIGAN
LINE. WILL MENTION IN HWO AND ALLOW FUTURE SHIFTS TO THROW INTO
GRIDS IF NEEDED AS WE APPROACH TOMORROW NIGHT.
HIGH DEW POINT AIR OVER COOLER SHELF WATERS COULD POSSIBLY ALLOW
FOR THE FORMATION OF NEAR SHORE SEA FOG THIS EVENING AND MOVE A
FURTHER INLAND THROUGH WEDNESDAY. IF THIS OCCURS...DENSE POCKETS OF
NEAR COASTAL FOG WILL HANG IN THERE THROUGH THURSDAY AM'S COLD FROPA.
MODELS HAVE SLOWLY BACKED OFF ON A CHRISTMAS AND FOLLOWING WEEKEND
SIGNIFICANT COLD SNAP. CP AIR MASS UP IN THE NORTHERN PLAINS
DOESN'T LOOK OVERLY IMPRESSIVE WITH NEAR 20 F OVER MID TEEN TDS...BUT
THE KEY WORD WILL BE 'SIGNIFICANT' AS IT WILL STILL BE COLD DURING
THE HOLIDAY WEEKEND. CAA WILL STILL BE AMPLE ENOUGH TO KEEP
CHRISTMAS AND SUBSEQUENT DAYS STRUGGLING TO ACHIEVE THE LOWER TO
MIDDLE 50S. WINDS GOING CALM UNDER CLEAR SKIES WILL DIVE MANY FAR
INTERIOR THERMOMETERS TO RIGHT AROUND..OR A TOUCH UNDER...FREEZING
OVER BOTH SATURDAY AND SUNDAY MORNINGS. NON-COASTAL COMMUNITIES
SOUTH OF INTERSTATE 10 WILL STILL FALL INTO THE MIDDLE 30S BY
SUNRISE...LOW TO MID 40S AT COAST.
LOWERING SOUTHWESTERN GULF PRESSURES AHEAD OF AN EVENTUALLY
PROGGED BROAD TROUGH MON-TUES WILL INCREASE RAIN CHANCES FROM THE
COASTAL BEND NORTHWARD FROM MID-LATE SUNDAY THROUGH EARLY TUESDAY.
AN UPPER LOW (SIMILAR TO TOMORROW'S) WILL LIFT OUT AND DRAG ANOTHER
COLD FRONT THROUGH SOMETIME ON TUESDAY. REINFORCING WEEKEND HIGH
KEEPING A DRY AND COOL NE FLOW OVER REGION DURING THE START OF
NEXT WEEK...LOOKING LIKE IT WILL NOT ALLOW A WAA PATTERN TO
DEVELOP. AS WE HEAD INTO THE FINAL DAYS OF 2009...TEMPS WILL STILL
REMAIN COOL AND EVENTS ARE SHAPING UP FOR A EARLY WINTER COLD RAIN
(FROZEN PRECIP UP NORTH) FOR SE TEXAS. 31
&&
.MARINE...
WINDS/SEAS HAVE INCREASED AS EXPECTED AS GRADIENT TIGHTENS. COOLER
WATERS NEAR THE COAST AND BAYS HAS KEPT SPEEDS DOWN THERE AND WOULD
EXPECT THIS TO CONTINUE. WILL POST A SCA FOR THE 20-60NM GROUP FOR
THE NEXT FCST PACKAGE. MAY NEED THE CAUTION FLAGS IN THE NEARSHORE
GROUP TOMORROW AS SEAS INCREASE FURTHER. CONDITIONS BECOMING MORE
FAVORABLE FOR SOME SEA FOG DEVELOPMENT BUT IF/WHEN IT ACTUALLY FORMS
IS DIFFICULT TO TELL (BEACH CAMS LOOK FINE AS OF RIGHT NOW). DIDN'T
CHANGE FRONTAL TIMING MUCH. EXPECT IT TO MOVE OFF THE COAST BETWEEN
3-6 AM (WEST-TO-EAST) THURS MORNING WITH STRONG OFFSHORE FLOW INT
ITS WAKE. WINDS WILL GRADUALLY BACK TO THE NE OR ENE THIS WEEKEND
WITH MEDIUM RANGE MODELS HINTING AT A COASTAL LOW DEVELOPING LATER
IN THE WEEKEND OR EARLY NEXT WEEK. 47
&&
.1123 AM AVIATION...
ISO/SCT SHRA CONTINUE MOVING SSW TO NNE ACROSS THE AREA UNDER
STRENGTHENING LOW LEVEL JET. EXPECT THIS TO CONTINUE FOR THE NEXT
24+ HOURS. KIND OF DIFFICULT TO PINPOINT FAVORED AREA/COVERAGE/TIMING
AS THERE IS NO SFC BOUNDARY TO REALLY WORK OFF OF. THAT BEING
SAID...WON'T COMPLICATE TAFS WITH PROB30'S/TEMPO'S THRU THE ENTIRE
PD. WILL JUST TRY AND FOCUS ON THE FIRST SEVERAL HOURS AND GO FROM
THERE. BEST COVERAGE FOR THE REMAINDER OF THE DAYLIGHT HOURS WILL
LIKELY BE EAST OF A MATAGORDA BAY TO CROCKETT LINE. REMAINDER OF
THE AREA WILL PROBABLY SEE EQUAL CHANCES LATE TONIGHT/WED AS JET
STRUCTURE BECOMES MORE FAVORABLE. CONDITIONS ALSO BECOMING
FAVORABLE FOR SOME SEA FOG DEVELOPMENT TONIGHT BUT CONFIDENCE AS
TO WHEN IS NOT HIGH SO WILL NOT TAKE CIG/VISBY'S DOWN TOO MUCH
ATTM. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 62 71 49 61 33 / 40 50 60 20 10
HOUSTON (IAH) 63 72 54 62 36 / 40 50 60 20 10
GALVESTON (GLS) 62 70 58 64 41 / 30 50 60 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE WEDNESDAY NIGHT
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 AM CST THURSDAY 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.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING
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...31/47
