[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141802
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE NOV 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1745 UTC.

...TROPICAL WAVES...
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 42W SOUTH OF 15N
MOVING WEST 10 TO 15 KT. THIS WAVE EXHIBITS A BROAD INVERTED V
PATTERN ON THIS AFTERNOONS VIS IMAGERY. SCATTERED MODERATE
CONVECTION IS FROM 8N-16N BETWEEN 38W-45W. THE ASSOCIATED CLOUD
TOPS ARE BEING STRETCHED TO THE NE WITH UPPER SW FLOW AROUND A
RIDGE JUST E OF THE AREA.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 52W SOUTH OF 17N
MOVING WEST 10 TO 15 KT. A QUIKSCAT PASS EARLIER THIS MORNING
DEPICTED THE WAVE FAIRLY WELL. SCATTERED MODERATE FROM 11N-15N
BETWEEN 48W-54W. ASSOCIATED TOPS ALSO BEING SHEARED TO THE NE.

A CENTRAL CARIBBEAN SEA TROPICAL WAVE IS ALONG 71W SOUTH OF 16N
MOVING WEST 10 TO 15 KT. THERE DOES APPEAR TO BE A LITTLE
CYCLONIC CURVATURE IN THE LOW CLOUD FIELD...BUT IT IS DIFFICULT
TO TELL IF THAT IS REALLY FROM THE WAVE...OR JUST A NATURAL
BYPRODUCT OF THE TRADE FLOW SPREADING THROUGH THE CENTRAL
CARIBBEAN AND AROUND THE ADJACENT OROGRAPHY. REGARDLESS...NO
ASSOCIATED DEEP CONVECTION NOTED WITH DRY MID TO UPPER AIR
DOMINATING THE AREA.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 9N14W 6N30W 10N45W 12N55W
10N62W. ASIDE FROM THE CONVECTION ASSOCIATED WITH THE TROPICAL
WAVES...ISOLATED MODERATE FROM 6N-10N BETWEEN 30W-38W. THE
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IN THE
SW CARIBBEAN OFF PANAMA ALSO ATTRIBUTED TO THE ITCZ.

...DISCUSSION...
THE GULF OF MEXICO...
OVERALL ZONAL MID TO UPPER FLOW WITH JUST A FEW MINOR
PERTURBATIONS NOTED IN WV IMAGERY THIS AFTERNOON. MOSTLY DRY AIR
DOMINATING THE GULF N OF 25N...WHILE DEBRIS UPPER MOISTURE IS
FOUND TO THE SOUTH...WHICH IS DOWNSTREAM FROM EPAC CONVECTION
INCLUDING THAT FROM RECENTLY UPGRADED TROPICAL STORM SERGIO.
DEEP CONVECTION IS MINIMAL OVER THE GULF ASIDE FROM A FEW CELLS
SEEN JUST S OF LOUISIANA IN WARMER/LESS STABLE AIR. A WEAK 1016
MB SFC HIGH WAS ANALYZED OVER N FLORIDA ON THE 1500 UTC MAP.
WINDS ARE GENERALLY LIGHT AND SEAS LOW E OF 80W. W OF
80W...10-15KT SLY FLOW BEING OBSERVED WITH ASSOCIATED AND 2-3 FT
S WIND WAVES. RAPIDLY INCREASING WINDS AND SEAS ANTICIPATED WITH
THE NEXT FRONTAL SYSTEM TO MOVE THROUGH THE GULF TOMORROW AND
THURSDAY...SEE MIAOFFNT4 FOR DETAILS.

THE CARIBBEAN SEA...
UPPER ZONAL FLOW IN THE NW CARIBBEAN IS ADVECTING HIGH MOISTURE
INTO THE REGION DOWNSTREAM FROM EPAC CONVECTION. SMALL CLUSTER
OF MODERATE CONVECTION NOTED OFF THE COAST OF THE YUCATAN NEAR
19N86W...OVER A WEAK REGION OF LOW LEVEL CONFLUENCE. AN UPPER
RIDGE AXIS EXTENDS NW THROUGH THE WRN CARIBBEAN FROM AN ORIGIN
NEAR NRN COLOMBIA. MOSTLY DRY MID TO UPPER AIR OVER THE ERN
CARIBBEAN...WITH AN UPPER TROUGH ALIGNED JUST E OF THE WINDWARD
ISLANDS. TRADES ARE FAIRLY LIGHT...15KT OR BELOW...WITH A WEAKER
PRESSURE PATTERN NOTED AT THE SFC. FAIRLY WEAK GRADIENT EXPECTED
TO PERSIST THROUGH TOMORROW.

THE ATLANTIC OCEAN...
STATIONARY FRONT ENTERS THE SW NORTH ATLC AT 31N68W AND
CONTINUES SE THROUGH THE CENTRAL BAHAMAS. NO ASSOCIATED DEEP
CONVECTION NOTED...WITH THE BOUNDARY INSTEAD MARKED BY A RAGGED
LINE OF LOWER TO MID CLOUDS. ASSOCIATED UPPER SUPPORT IS
WEAKENING WELL N OF THE AREA. UPPER RIDGE EXTENDING NE INTO THE
SW NORTH ATLC ALSO ADVECTING ABUNDANT HIGH MOISTURE INTO THE
AREA JUST E OF THE BAHAMAS. NEXT INTERESTING FEATURE IS THE DEEP
LAYER LOW NEAR 29N47W THAT HAS A 1009 MB SFC LOW IN THE
VICINITY. CONVECTION REMAINS MINIMAL WITH JUST ISOLATED SHOWERS
NOTED WITHIN 200 NM OF ANY SIDE OF THE LOW. HOWEVER...AS THIS
SYSTEM CONTINUES TO INTERACT WITH THE STRONG 1040 MB BLOCKING
HIGH TO ITS NORTH NEAR NEWFOUNDLAND...IT WILL SEND A SMALL TO
MODERATE ENE SWELL TO EXPOSED FLORIDA AND BAHAMA BEACHES LATER
THIS WEEK. THIS SYSTEM WAS PREVIOUSLY ANALYZED AS AN OCCLUDED
SYSTEM...WITH LESS TEMPERATURE GRADIENT NOW NOTED A PAIR OF SFC
TROUGHS ANALYZED WITH THE ASSOCIATED CONFLUENT ZONES IN THE
VICINITY. THE FIRST IS ALONG 21N54W 26N46W THEN CONNECTS TO THE
SFC LOW. THE OTHER IS FURTHER E ALONG 23N42W 28N37W 31N26W. THE
LATTER HAS MORE CONVECTION WITH SCATTERED SHOWERS/TSTMS NOTED
WITHIN 100 NM EITHER SIDE. PRONOUNCED UPPER RIDGING EXTENDS
THROUGH THE E ATLC ALONG 32W. SFC HIGH PRESSURE ALSO DOMINATING
THE E ATLC WITH A 1018MB CENTER NEAR 26N28W.

$$
WILLIS




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