[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121727
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI JAN 12 2007

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...
METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG THE PRIME MERIDIAN AT 4N AND
CONTINUES W THROUGH 4N20W 3N30W 1N40W BEFORE CROSSING THE
EQUATOR AT 45W. SCATTERED MODERATE CONVECTION FROM THE EQUATOR
TO 6N BETWEEN 27W-48W.

...DISCUSSION...
GULF OF MEXICO...
A 1038 MB SFC HIGH PRESSURE OVER THE W ATLANTIC IS PRODUCING
10-20 KT RETURN FLOW OVER THE GULF OF MEXICO.  THIS IS
GENERATING MODERATE E TO SE WIND WAVES/SWELL ACROSS THE GULF.  A
BIT HIGHER WINDS/SEAS SHOULD BE ANTICIPATED IN THE STRAITS OF
FLORIDA. THE GULF REMAINS VOID OF ANY SIGNIFICANT
CONVECTION...WITH WIDELY SCATTERED PATCHES OF LOW
CLOUDS/MOISTURE SEEN ROTATING AROUND THE AFOREMENTIONED
ANTICYCLONE. IN THE UPPER LEVELS... A LARGE SCALE RIDGE
CONTINUES TO DOMINATE THE GULF IN ADDITION TO THE SE US. THIS IS
ADVECTING A BAND OF UPPER LEVEL MOISTURE FROM THE NE PACIFIC TO
N MEXICO AND TEXAS...AND CLIPS THE NRN GULF WATERS...PRODUCING
BROKEN TO OVERCAST HIGH CLOUDS.  EXPECT SURFACE WINDS AND WAVES
TO CONTINUE TO VEER IN DIRECTION INTO THE WEEKEND AS THE HIGH
SLIDES FURTHER OFF THE EAST COAST IN ADVANCE OF THE NEXT FRONT
TO MOVE INTO THE NW GULF DURING MONDAY.

CARIBBEAN SEA...
FRESH TO STRONG TRADES DOMINATE THE CARIBBEAN BASIN ON THE SRN
PERIPHERY OF STRONG HIGH PRESSURE PUSHING OFF THE EAST COAST.
THIS CONTINUES TO ADVECT PATCHES OF LOW LEVEL MOISTURE WITH
EMBEDDED SHOWERS ACROSS THE BASIN. SIMILAR TRADES ANTICIPATED
THROUGH THE WEEKEND. A MORE EXTENSIVE AREA OF LOW LEVEL MOISTURE
IS SEEN MOVING THROUGH TRINIDAD...NE VENEZUELA...AND THE ABC
ISLANDS. GFS MOISTURE FIELDS CONTINUE TO INITIALIZE THIS AREA
FAIRLY WELL...AND SUGGEST THE AREA WILL REMAIN QUASI STATIONARY
OVER THE NEXT COUPLE OF DAYS. THUS...LIGHT TO MODERATE
PRECIPITATION CAN BE EXPECTED FOR THE AREA INTO THE WEEKEND. IN
THE UPPER LEVELS...RIDGING IS NOTED W OF 80W. THE BASE OF A
POSITIVELY TILTED UPPER TROUGH EXTENDS SW THROUGH THE CARIBBEAN
WATERS BETWEEN JAMAICA AND HISPANIOLA. UPPER FLOW IS MOSTLY
ZONAL IN THE E CARIB. EXTENSIVE DRY AIR CONTINUES TO HOVER OVER
THE CARIBBEAN ABOVE 500 MB.

ATLANTIC OCEAN...
STRONG SFC HIGH PRESSURE IS WELL ESTABLISHED OVER THE WRN ATLC
WITH A 1038 MB CENTER NEAR 37N65W. THE HIGH CONTINUES SLIDING E
FROM THE EAST COAST BEHIND THE COLD FRONT THAT ENTERS THE AREA
AT 32N45W AND CONTINUES SW THROUGH 22N67W...AND THEN BECOMES
STATIONARY THROUGH THE COAST OF ERN CUBA. SHOWERS LIKELY WITHIN
60NM OF THIS BOUNDARY. THE SMALL PATCH OF MODERATE CONVECTION
NEAR THE TURKS AND CAICOS ISLANDS IS BEING INFLUENCED...IN
ADDITION TO THE SFC FRONTAL BOUNDARY...BY THE DYNAMICS AROUND
THE UPPER TROUGH EXTENDING THROUGH THE AREA. FRESH TO STRONG E
TO NE WINDS ARE COMMON BEHIND THE FRONT...WHICH ARE GENERATING
LARGE E/NE WIND WAVES AND SWELL. THIS WILL GRADUALLY RELAX AS WE
MOVE THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK...AS THE HIGH
PUSHES E WHILE WEAKENING IN ADVANCE OF THE NEXT FRONT. MUCH OF
THE CENTRAL ATLC WATERS BETWEEN THE FRONT AND 30W ARE DOMINATED
BY RIDGING AT ALL LEVELS...WITH PATCHES OF LOW LEVEL MOISTURE
AND EMBEDDED SHOWERS BEING ADVECTED WWD WITH MODERATE E FLOW. IN
THE ERN ATLC...A PRONOUNCED UPPER LOW CONTINUES TO SPIN NEAR
30N24W. THIS HAS A WEAK 1018 MB SFC REFLECTION NEAR 27N26W. MOST
OF THE ASSOCIATED CONVECTION IS LIMITED TO THE E PORTION OF THE
UPPER TROUGH AXIS...WITH SCATTERED SHOWERS WITH EMBEDDED
CLUSTERS OF MODERATE CONVECTION N OF 25N BETWEEN 15W-25W...WHICH
INCLUDES THE CANARY ISLANDS. WLY JET OVER THE DEEP TROPICS
CONTINUES TO ADVECT BROKEN TO OVERCAST HIGH CLOUDS EWD FROM NE
SOUTH AMERICA THROUGH AFRICA.

$$
WILLIS




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