[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 120544 CCA
TWDAT

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SUN NOV 12 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE
AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION
IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

CORRECTION MADE FOR TIME IN SURFACE ANALYSIS

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 59W S OF 15N MOVING W 10 TO 15 KT. THIS
WAVE HAS BECOME A WEAK LOW AMPLITUDE FEATURE AFTER PERSISTENT
STRONG WLY UPPER LEVEL WINDS AND WIDESPREAD STRONG SUBSIDENCE
HAVE TAKEN TOLL. NO DEEP CONVECTION OR ORGANIZED CLOUDINESS IS
ASSOCIATED WITH THIS WAVE AND IT WILL LIKELY CONTINUE TO TRACK W
AS A SHALLOW FEATURE.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N15W 6N31W 7N45W 10N57W 10N62W.
THE AXIS REMAINS QUIET WITH ONLY ONE AREA OF SCATTERED MODERATE
CONVECTION FROM 5N-7N BETWEEN 27W-31W.

...DISCUSSION...
GULF OF MEXICO...
A MODERATE COLD FRONT IS TRACKING ACROSS THE AREA...AS OF 03Z IT
WAS ANALYZED FROM THE FL PANHANDLE TO 24N90W CONTINUING TO THE
COAST OF S MEXICO NEAR 19N95W. THE FRONT IS THEN HUNG UP ALONG
THE E SLOPES OF THE SIERRA MADRE IN MEXICO. N-NE WINDS FROM 20
TO 30 KT ARE COMMON BEHIND THE FRONT AS STRONG HIGH PRES HAS
BUILT SWD ACROSS THE SRN PLAINS. TEMPS AND DEWPOINTS HAVE ALSO
DROPPED NOTICEABLY...FROM THE 60'S AND 70S' ACROSS MUCH OF THE
FL PENINSULA TO DEWPOINTS MAINLY IN THE 50'S AND TEMPS IN THE
50'S AND 60'S BEHIND THE BOUNDARY. THE FRONT IS NOT EASILY
DEFINED USING NIGHT CHANNEL VIS IMAGES AS THERE IS A LOT OF
UPPER-LEVEL MOISTURE MASKING ANY LOW-LEVEL SIGNAL. THIS UPPER
LEVEL MOISTURE IS WIDESPREAD ACROSS THE GULF AS IT IS
CONTINUOUSLY BEING ADVECTED FROM A LARGE AREA OF UNSETTLED
WEATHER IN THE EPAC ASSOCIATED WITH THE REMNANTS OF ROSA AND
SHORT-LIVED T.D. 20-E. SCATTERED SHOWERS ARE EMBEDDED IN THIS
MOISTURE PLUME N OF 24N W OF 88W. THE FRONT WILL CONTINUE TO
SLIDE SE AND WEAKEN THRU THE DAY.

CARIBBEAN...
THE CARIB REMAINS QUIET THIS EARLY MORNING WITH PLENTY OF
DRY/STABLE SINKING AIR ALOFT IN PLACE. THE MID-UPPER LEVEL
PATTERN PRODUCING THIS STABLE ENVIRONMENT CONSISTS OF AN UPPER
RIDGE CENTERED IN THE WRN CARIB NEAR 16N81W AND SLIGHT RIDGING E
OF THE AREA IN THE TROPICAL ATLC. A WEAKNESS LIES ABOVE THE
CNTRL CARIB INDUCED BY A WEAKENING TROUGH TO THE N/NE. THE ONLY
AREA OF SIGNIFICANT WEATHER IS IN THE EXTREME SW CARIB WHERE
SCATTERED MODERATE CONVECTION IS S OF 11N BETWEEN
76W-81W...ASSOCIATED WITH THE ITCZ. THERE ARE ALSO SCATTERED
SHOWERS AND TSTMS ACROSS PORTIONS OF NRN CENTRAL AMERICA
ENHANCED BY UPPER DIFFLUENCE AND ENHANCED LOW-LEVEL LIFT AHEAD
OF THE COLD FRONT IN THE GULF. OVERALL...LITTLE CHANGE IS
EXPECTED OVER THE NEXT FEW DAYS AS DRY AIR REMAINS ESTABLISHED
ACROSS THE AREA. TRADE WINDS ARE MODERATE AND WILL LIKELY REMAIN
THAT WAY OR SLACKEN SOME OVER THE NEXT FEW DAYS AS THE COLD
FRONT IN THE GULF...OR MORE LIKELY REMNANTS OF...STALL ACROSS
THE NW PORTION OF THE CARIB.

ATLANTIC OCEAN...
THE MID TO UPPER LEVEL PATTERN ACROSS THE SUBTROPICAL AND
TROPICAL ATLC HAS SIGNIFICANTLY FLATTENED. SLIGHT ELONGATED
RIDGING STRETCHES NWD FROM THE WRN CARIBBEAN ACROSS THE BAHAMAS
TOWARDS BERMUDA. A WEAKENING TROUGH LIES E OF THE RIDGE FROM A
CUT OFF NEAR 33N52W SOUTHWESTWARD TO THE MONA PASSAGE. THE CUT
OFF LOW IS VERTICALLY STACKED AND ANALYZED AT 1008 MB AT THE SFC
WITH A DISSIPATING COLD FRONT ALONG 32N50W 24N55W 21N63W THEN
STATIONARY TO THE N COAST OF HISPANIOLA. ISOLATED SHOWERS ARE
WITHIN 90 NM OF THE FRONT. THE TRANSITION FROM AN UPPER TROUGH
TO A STACKED LOW WAS WELL FORECAST BY THE GFS. THE UPPER LEVEL
FLOW BECOMES NEARLY ZONAL E OF 60W...WHICH IS A SIGNIFICANT
CHANGE FROM THE PAST FEW DAYS...AS THE LARGE CUT OFF LOW IN THE
E ATLC HAS PULLED N OF THE AREA NEAR 33N29W AND WEAKENED. AN
ILL-DEFINED SFC TROUGH ASSOCIATED WITH THIS LOW EXTENDS FROM
32N25W TO 23N27W. A FAIR AMOUNT OF MAINLY HIGH LEVEL MOISTURE
LIES N OF 23N E OF 30W. OTHERWISE...DRY AND STABLE AIR ALOFT
COVERS MOST OF THE REMAINDER OF THE ATLC N OF 13N KEEPING
CONDITIONS QUIET. IN THE DEEP TROPICS...THE ONCE PRONOUNCED
UPPER-LEVEL JET THAT EXTENDS FROM S AMERICA TO AFRICA HAS
SUBSTANTIALLY WEAKENED BUT IS STILL PRODUCING PATCHES OF
SCATTERED SHOWERS FROM 9N-12N BETWEEN 35W-50W. GFS FORECASTS THE
WEATHER PATTERN TO BECOME MORE AMPLIFIED IN THE CENTRAL/WRN ATLC
OVER THE NEXT COUPLE DAYS WHILE STAYING RATHER ZONAL IN THE E
ATLC.

$$
CANGIALOSI




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