[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 242353
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST FRI DEC 24 2010

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 4N8W 2N19W 2N44W CROSSING THE
EQUATOR NEAR 50W. SCATTERED MODERATE CONVECTION IS FROM THE
EQUATOR TO 2N BETWEEN 8W-11W. ISOLATED MODERATE CONVECTION DOTS
THE AREA FROM S OF 5N W OF 42W TO INLAND OVER SOUTH AMERICA.

...DISCUSSION...

GULF OF MEXICO...
GULF REMAINS FAIRLY QUIET IN THE WAKE OF THE RECENT FRONTAL
PASSAGE. AN UPPER RIDGE DOMINATES THE GULF EXTENDING FROM THE W
CARIBBEAN WITH MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR
ALOFT COVERING THE S GULF. THE SURFACE RIDGE NOW DOMINATES THE
GULF ANCHORED BY A 1028 MB HIGH OVER THE W OHIO VALLEY GIVING
THE GULF RETURN SURFACE FLOW. AN UPPER SHORTWAVE/LOW IS OVER THE
CENTRAL TEXAS WITH THE ACCOMPANYING COLD FRONT/SURFACE LOW
MOVING RAPIDLY TOWARD THE TEXAS COAST AND THE NW GULF WITH
POSSIBLE ISOLATED SHOWERS PRECEDING THE FRONT OVER THE NW GULF
FROM 25N-29N W OF 93W TO INLAND OVER SE TEXAS. THIS FRONT SHOULD
ENTER THE GULF LATER TONIGHT CROSSING THE GULF THEN EXITING THE
GULF LATE SUN/EARLY MON.

CARIBBEAN SEA...
UPPER RIDGE DOMINATES THE W CARIBBEAN EXTENDING N OVER THE GULF
OF MEXICO AND THE FAR W ATLC. THE UPPER TROUGH OVER THE
REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC DIPS S OVER THE
N/CENTRAL CARIBBEAN TRAILING A COLD FRONT JUST N OF THE GREATER
ANTILLES.  STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT DOMINATES
THE W CARIBBEAN W OF A LINE FROM THE VIRGIN ISLANDS TO NICARAGUA
NEAR THE COSTA RICA BORDER. A LOW/MID LEVEL SHEAR AXIS THAT
EXTENDS FROM THE W TROPICAL ATLC NEAR 16N57W ACROSS THE LESSER
ANTILLES NEAR MARTINIQUE ALONG 13N70W 11N80W TO PANAMA NEAR
9N81W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS
WITHIN 90 NM EITHER SIDE OF THE SHEAR AXIS. MOISTURE AND THUS
SHOWERS ARE EXPECTED TO REMAIN ACROSS THE S CARIBBEAN THROUGH
THE WEEKEND WITH A COLD FRONT ENTERING THE W CARIBBEAN SUN
EVENING.

ATLANTIC OCEAN...
AN THE UPPER RIDGE THAT COVERS THE W CARIBBEAN AND GULF OF
MEXICO EXTENDS OVER THE FAR W ATLC W OF 70W. A BROAD DEEP LAYER
TROUGH COVERS THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC
SUPPORTING A COLD FRONT THAT ENTERS THE CENTRAL ATLC NEAR 32N45W
EXTENDING ALONG 25N54W JUST N OF THE GREATER ANTILLES NEAR
20N68W THEN TURNING WNW TO THE N COAST OF CUBA NEAR 23N81W.
ISOLATED SHOWERS ARE WITHIN 30 NM E OF THE FRONT WITH DENSE LOW
LEVEL CLOUDS AND POSSIBLE ISOLATED SHOWERS WITHIN 90 NM W OF THE
FRONT WITH WINDS DROPPING BELOW GALE FORCE AT 25/0000 UTC. COLD
AIR STRATOCUMULUS CLOUDS COVER THE REMAINDER OF THE ATLC W OF
THE FRONT. AN UPPER RIDGE AXIS EXTENDS FROM THE W TROPICAL ATLC
NEAR 11N54W NE ALONG 17N52W TO BEYOND 32N35W. DIFFLUENCE ALOFT
TO THE NW OF THE UPPER RIDGE AXIS IS ENHANCING CLUSTERS OF
SCATTERED SHOWERS WITHIN 120 NM OF LINE FROM 22N46W TO OVER THE
LESSER ANTILLES NEAR GUADELOUPE. A SURFACE TROUGH IS EMBEDDED
BELOW THIS UPPER RIDGE EXTENDING ALONG 29N37W TO 23N43W WITH
SCATTERED SHOWERS WITHIN 150 NM E OF THE TROUGH AXIS. A SECOND
SURFACE TROUGH IS IN THE W TROPICAL ATLC ALONG 18N53W TO 12N54W
WITH SCATTERED SHOWERS WITHIN 120 NM E OF THE TROUGH AXIS. THE E
ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1019 MB HIGH
W OF THE CANARY ISLANDS NEAR 27N23W GIVING THE REMAINDER OF THE
E ATLC FAIR WEATHER THIS EVENING.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
PAW





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