[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 081032
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED APR 08 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N9W 3N18W 2N26W CROSSING THE
EQUATOR NEAR 34W AND EXTENDING TO 1S40W INTO NE BRAZIL NEAR
4S45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM
1N-5N E OF 4W. SCATTERED MODERATE CONVECTION IS FROM 1N-6N
BETWEEN 14W-23W. SIMILAR CONVECTION IS S OF 4N BETWEEN 23W-31W.

...DISCUSSION...

GULF OF MEXICO...
WEAKENING 1023 MB HIGH PRES IS CENTERED NEAR 25N92W WITH A
SECONDARY CENTER LOCATED OVER SRN MEXICO. SFC OBSERVATIONS AND
RECENT SCATTEROMETER PASSES REVEAL DIMINISHING NW 15-20 KT WINDS
OVER THE FAR ERN WATERS...DUE TO THE PRESSURE GRADIENT
BETWEEN THE RIDGE AND A COLD FRONT E OF THE AREA. SEAS HAVE BEEN
STEADILY SUBSIDING BUT STILL REMAIN ELEVATED UP TO 8 FT OVER
THE ERN WATERS. THE COOL AIRMASS IS BEING MODIFIED OVER THE W
GULF AS SLY RETURN FLOW HAS SET UP. THIS PROCESS WILL SPREAD E
THROUGHOUT THE DAY TODAY AS THE SFC HIGH IS EXPECTED TO MOVE E
INTO THE W ATLC TONIGHT. IN THE MID AND UPPER LEVELS...A WLY JET
WITH CORE WINDS NEAR 110 KT OVER THE SRN HALF OF THE REGION IS
ADVECTING HIGH LEVEL CLOUDINESS S OF 22N. AN UPPER TROUGH
CURRENTLY OVER THE W COAST OF THE U.S. WILL MOVE INTO THE
CENTRAL PLAINS LATE TOMORROW DRAGGING A FRONT NEAR THE FAR NW
WATERS.

CARIBBEAN SEA...
A LATE SEASON COLD FRONT REMAINS WELL DEFINED OVER THE NW
CARIBBEAN EXTENDING FROM E CUBA TO THE HONDURAS/NICARAGUA
BORDER. BROKEN LOW-MID LEVEL CLOUDINESS AND EMBEDDED ISOLATED
SHOWERS ACCOMPANY THE FRONT WITHIN 90 NM. N-NW 20 KT WINDS
FOLLOW THE FRONT. E OF THE BOUNDARY...CONDITIONS ARE MAINLY FAIR
ENHANCED BY WIDESPREAD STABLE AIR IN THE MID AND UPPER LEVELS.
HOWEVER...THERE ARE A FEW SHOWERS OVER HISPANIOLA ASSOCIATED
WITH A REMNANT LOW-LEVEL TROUGH. TRADE WINDS ARE FAIRLY RELAXED
DUE TO AFOREMENTIONED LARGE SCALE TROUGHING N AND W OF THE AREA
AND WILL LIKELY REMAIN THAT WAY THROUGH THU.

ATLANTIC OCEAN...
LOW-LEVEL CONVERGENCE ALONG A STRONG COLD FRONT...FROM 32N65W TO
E CUBA...AND AN UPPER DIFFLUENT PATTERN IS TRIGGERING SCATTERED
SHOWERS AND TSTMS N OF 28N BETWEEN 62W-67W. WINDS REMAIN STRONG
ON BOTH SIDES OF THE BOUNDARY AND BASED ON AN EARLIER QSCAT PASS
ARE STRONGEST IN THE COLD SECTOR NEAR THE N BORDER. FARTHER E...
SCATTERED SHOWERS AND TSTMS ARE FROM 21N-27N BETWEEN 42W-47W
ASSOCIATED WITH INSTABILITY NEAR AN UPPER LOW. THIS UPPER
FEATURE DOES HAVE A SFC CONNECTION ANALYZED AS A TROUGH FROM
28N44W TO 20N48W. THE FLOW ALOFT IS MAINLY ZONAL ACROSS THE
SUBTROPICAL E ATLC SUPPORTING FAIR WEATHER. OVER THE TROPICS...A
SPRAWLING UPPER HIGH CENTERED OVER WRN AFRICA IS ENHANCING
CONVECTION WITHIN THE ITCZ. A 100+ KT SW TO W JET EXTENDS FROM
THE ERN CARIBBEAN NEAR 14N61W TO 19N40W TO 24N16W GENERATING AND
ADVECTING A SWATH OF MID-HIGH LEVEL MOISTURE WITHIN 300 NM SE OF
THE JET AXIS.

$$
CANGIALOSI





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