FXUS64 KCRP 142353 AAA
AFDCRP
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
553 PM CST MON DEC 14 2009
.DISCUSSION...SEE AVIATION SECTION AND UPDATED MARINE SECTION.
&&
.MARINE...DENSE SEA FOG CONTINUES TO GRADUALLY MOVE BACK INTO
THE MIDDLE TEXAS COASTAL WATERS AS LIGHT EASTERLY WINDS DEVELOP
ALONG THE COAST. VISIBILITY IS DOWN TO 1/2 MILE AT PORT LAVACA
AND LOWERING ELSEWHERE ALONG THE COAST. ISSUED A DENSE FOG
ADVISORY FOR THE BAYS AND NEARSHORE WATERS FOR VISIBILITY
RESTRICTION TO 1 MILE OR LESS THROUGH 6 AM TUESDAY. EXPECT THE
WINDS WILL BE INCREASING FROM THE NORTH BY 6 AM AS THE COLD
FRONT MOVES THROUGH.
&&
.AVIATION...A MOIST AND STABLE BOUNDARY LAYER WILL REMAIN ACROSS
SOUTH TEXAS THROUGH THE OVERNIGHT HOURS. SEA FOG LURKING OFF THE
BARRIER ISLAND IS EXPECTED TO GRADUALLY SPREAD INLAND THROUGH THE
EVENING HOURS ADVECTING LIFR CIGS/VSBYS ACROSS KCRP/KALI/KVCT BEFORE
MIDNIGHT. IFR/LIFR CIGS SHOULD REMAIN ACROSS KLRD TONIGHT. THESE
CONDITIONS ARE EXPECTED TO PERSIST AFTER MIDNIGHT AHEAD OF A COLD
FRONT. THE FRONT SHOULD BE THROUGH KVCT AROUND 15Z AND
KCRP/KALI/KLRD BY 17Z. VSBYS SHOULD IMPROVE TO VFR BEHIND THE FRONT
AS NORTHERLY SURFACE WINDS INCREASE TO 15-20KT WITH 25KT GUSTS
POSSIBLE. HOWEVER...MVFR CIGS WITH -RA SHOULD DEVELOP AND PERSIST
AREAWIDE TUESDAY AFTERNOON BEHIND THE FRONT.
&&
.PREV DISCUSSION... /ISSUED 349 PM CST MON DEC 14 2009/
SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...WEAK 850 MB
WARM FRONT MOVING ACROSS NORTHERN AREAS AND INVERTED TROUGHINESS
IN THE OFFSHORE WATERS. THE TROUGH HAS BEEN PRODUCING LINES
OF WEAK SHOWERS MOVING INTO PORT OCCONNOR SINCE LATE MORNING.
OTHERWISE WESTERN AREAS ARE STABLE WITH SOLID STRATUS...HIGHER
DEWPOINTS IN THE MID TO UPPER 60S HAVE ENTERED THE COASTAL
BEND AND STRATUS IS BECOMING CUMULIFORM ALLOWING SMALL BREAKS
OF SUN AND TEMPS NOW AROUND 70. GPS SENSOR DEPICTS PRECIPITABLE
WATER UP TO 1.3 INCHES. MODELS DEPICT STRATUS FILLING BACK INTO THIS
EVENING WITH THE POTENTIAL FOR NEARSHORE SEA FOG AGAIN WITH LIGHT
WINDS...AS WELL AS FOG INLAND WITH SUCH HIGH DEWPOINTS AND LIGHT
WIND. COLD FRONT EXPECTED IN THE FAR NORTHERN AREAS AROUND
MIDNIGHT AND CRP BY ABOUT 4 AM. AN AREA OF RAIN AND ISOLATED
THUNDERSTORMS WILL FORM BEHIND THE FRONT 06 TO 12Z IN THE NORTHERN
COASTAL BEND AND 12 TO 18Z FOR THE SOUTHERN COASTAL BEND. WINDY
CONDITIONS BEHIND THE FRONT INCREASE TUESDAY MORNING. MODELS PROG
THE LEFT FRONT QUAD OF A JET STREAK AT 250 MB PLACING A PERIOD OF
GOOD UPPER DIVERGENCE THAT SHOULD FOCUS AN AREA OF RAIN. ELEVATED
INSTABILITY SUPPORTS SOME THUNDERSTORMS. THEN A BREAK IN
PRECIPITATION FOR SEVERAL HOURS FOR THE COASTAL BEND UNTIL THE
INCOMING DIGGING UPPER LOW NEARS. BOTH THE GFS AND NAM DEPICT RAIN
ENHANCING OVER THE RIO GRANDE VALLEY TUESDAY AFTERNOON...IN
RESPONSE TO AN H850 TO 700 MB CIRCULATION AND THERMAL GRADIENT.
GFS IS NOW INLINE WITH THE ECMWF AND NAM RECENT RUNS WHICH
SPREAD RAIN FROM THE RIO GRANDE AND ACROSS THE COASTAL BEND
TUESDAY NIGHT AHEAD OF AN UPPER LOW DIGGING OVER MEXICO. RATHER
STRONG SOUTHERLY JET STREAK ALOFT TRAVERSING THE COASTAL BEND
TUESDAY NIGHT AND SHOULD EXPAND AND ENHANCE RAINFALL. POTENTIAL
FOR AREAS OF HEAVY RAIN ESPECIALLY THE COASTAL BEND AND SOUTHERN
RIO GRANDE WHERE BEST DYNAMICS AND DEEPER 1.5 INCH PW MERGES.
1 TO 2 INCH RAINFALL IS POSSIBLE.
LONG TERM (WEDNESDAY THROUGH MONDAY)...WEDNESDAY LOOKS TO BE A WET
DAY. THE GFS HAS FINALLY FALLEN MORE IN LINE WITH THE NAM/ECMWF
WHICH KEEPS THE UPPER LOW CUT OFF OVR THE BIG BEND AREA. THE GFS IS
STILL A TAD FASTER AND SLIGHTLY MORE N THAN BOTH THE NAM AND ECMWF
BUT OVERALL THIS PATTERN WILL RESULT IN PRECIP THRU WED. THE MODELS
ARE SHOWING LARGE OMEGA VALUES ON WED ALONG WITH DIFFLUENCE ALOFT
AND THE TAIL END OF A 100KT JET. 500MB TEMPS DECREASE THRU WED AS
THE CORE OF THE UPPER LOW APPROACHES S TX. ALSO IN THE 850MB HEIGHT
FIELDS A BDRY IS EVIDENT WHICH WILL INCREASE LOW/MID LEVEL
CONVERGENCE. ALL OF THESE FACTORS COMBINED COULD PRODUCE ELEVATED
TSRA'S. HOWEVER...AM EXPECTING MAINLY SHRA'S GIVEN THE LOW LEVEL
STABILITY/LACK OF CAPE DUE TO A SFC HIGH OVER S TX IN THE WAKE OF A
COLD FRONT. SO MAIN INSTABILITY AND DYNAMICS WILL BE IN THE
MID/UPPER LEVELS. ONCE THE 850MB BDRY PUSHES S WED NIGHT...A DEEPER
NLY FLOW DVLPS. THERE IS STILL UPPER DYNAMICS IN PLACE THRU WED
NIGHT AS THE UPPER LOW MOVES ACROSS S TX...SO THERE REMAINS A CHC OF
RAIN INTO WED NIGHT. MAIN QUESTION IS WHEN WILL THE RAIN END? THE
GFS TAPERS THE PRECIP OFF BY THU MORNING WHILE THE ECMWF KEEPS
PRECIP ACROSS S TX WELL INTO THU DUE TO A SLIGHTLY SLOWER MVG UPPER
LOW. THE GFS DOES KEEP LOW/MID LEVEL MOISTURE IN PLACE THRU THU BUT
WITH THE UPPER LOW BEGINNINNG TO EXIT TO THE E...SUBSIDENCE DVLPS
WHICH THEN SHUTS OFF THE UPPER DYNAMICS MAKING FOR JUST A CLOUDY DAY
ON THU. HAVE TRENDED POPS TO SHOW A DECREASE WED NIGHT INTO THU
MORNING FROM W TO E. THU/FRI...MODELS ARE IN FAIR AGREEMENT WITH
RIDGING TAKING PLACE AND GENERALLY NO PRECIP. MAY EVEN SEE SOME
SUNSHINE LATE THU OR FRI. HOWEVER...A WEAK EMBEDDED SHORT WAVE MVG S
IN NLY FLOW ALOFT IS PROGD TO BRING A WEAK COLD FRONT THRU S TX FRI
NIGHT. AHD OF THE CF...SFC WINDS MAY BRIEFLY VEER S AND IN TURN
USHER IN LIMITED MOISTURE/CLOUDS. AM NOT EXPECTING PRECIP DUE TO
LACK OF SUFFICIENT MOISTURE AS THE FRONT MOVES THRU. MAINLY THE COLD
FRONT WILL HELP KEEP SEASONAL TEMPS IN PLACE THRU THE WEEKEND ALONG
WITH PC SKIES.
MARINE...DENSE FOG HAS THINNED AND STRATUS HAS BROKEN
UP WITH INCREASED INSTABLITY. HOWEVER WITH LIGHT WIND AND
DEWPOINTS IN THE UPPER 60S NEAR THE BAYS NOW IN THE UPPER
50S (SST) MORE FOG WILL DEVELOP AND DRIFT ALONG THE COAST
UNTIL THE COLD FRONT ARRIVES LATE TONIGHT AND TUESDAY MORNING.
SHOWERS WILL BE ISOLATED BUT INCREASE FROM NORTH TO SOUTH
AFTER MIDNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 56 60 47 55 46 / 30 60 70 60 30
VICTORIA 51 56 41 53 43 / 70 50 60 60 30
LAREDO 55 59 46 58 46 / 20 50 60 40 10
ALICE 55 58 46 55 45 / 30 50 60 60 30
ROCKPORT 57 61 49 56 47 / 50 60 70 60 30
COTULLA 52 57 43 56 41 / 30 40 50 30 10
KINGSVILLE 57 60 47 56 46 / 30 60 70 60 30
NAVY CORPUS 57 62 50 57 50 / 30 60 70 60 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 6 AM CST TUESDAY FOR THE FOLLOWING
ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O'CONNOR...
COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...
COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL
OUT 20 NM.
&&
$$
TMT/89...MARINE
TM/95...AVIATION
