[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260535
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST THU FEB 26 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N9W 3N15W CROSSING THE EQUATOR
NEAR 18W EXTENDING TO 4S29W INTO NE BRAZIL NEAR 2S47W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS S OF 4N BETWEEN 6W-15W.
SCATTERED MODERATE CONVECTION IS ALSO S OF 4N BETWEEN 37W-47W.

...DISCUSSION...

GULF OF MEXICO...
GENERALLY FAIR WEATHER IS PRESENT ACROSS MUCH OF THE GULF
REGION...WHERE NORTHWESTERLY FLOW ALOFT IS SUPPORTING
ATMOSPHERIC SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS. THE
SUBSIDENCE IS ALSO BEING SUPPORTED BY A SURFACE RIDGE OVER THE
GULF...WHICH EXTENDS SOUTHWESTWARD FROM A 1032 MB SURFACE HIGH
OVER THE W ATLC NEAR 37N73W. ACROSS PORTIONS OF THE W GULF...SE
TO S SURFACE WINDS OF 15 TO 20 KT ARE PRESENT AROUND THE SURFACE
RIDGE. DEEP LAYER DRY AIR IS ALSO PRESENT ACROSS MUCH OF THE
GULF REGION. HOWEVER...UPPER LEVEL MOISTURE IS STREAMING
SOUTHEASTWARD ACROSS PORTIONS OF THE N GULF.

CARIBBEAN SEA...
A DEEP LAYER TROUGH OVER THE W ATLC IS ASSOCIATED WITH A SURFACE
STATIONARY FRONT THAT EXTENDS FROM E CUBA NEAR 20N74W
NORTHEASTWARD INTO THE W NORTH ATLC. LOW LEVEL CONVERGENCE IS
SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THIS
FRONT. GENERALLY FAIR WEATHER CONDITIONS ARE OCCURRING ACROSS
MUCH OF THE CARIBBEAN REGION...WHERE CONFLUENCE IN WESTERLY FLOW
ALOFT IS PRESENT. TRADE WINDS ARE FORECAST TO DIMINISH OVER MUCH
OF THE CARIBBEAN SEA THROUGH SUNDAY. PATCHES OF LOW LEVEL
MOISTURE CONTINUE TO BE ADVECTED WESTWARD ACROSS THE CARIBBEAN
BY THE TRADE WINDS...WITH SCATTERED SHOWERS EMBEDDED WITHIN
THESE PATCHES OF LOW LEVEL MOISTURE. THE GREATEST CONCENTRATION
OF THESE SHOWERS IS FROM 12N-16N E OF 68W. ALSO...INCREASED
UPPER LEVEL MOISTURE IS STREAMING NORTHEASTWARD ACROSS PORTIONS
OF THE SE CARIBBEAN.

ATLANTIC OCEAN...
THE DEEP LAYER TROUGH OVER THE W ATLC IS ASSOCIATED WITH A
SURFACE STATIONARY FRONT THAT EXTENDS FROM E CUBA NEAR 20N74W TO
26N63W TO 28N58W AND A SURFACE COLD FRONT THAT EXTENDS FROM
28N58W TO 30N55W TO 32N51W TO NE OF THE DISCUSSION AREA. LOW
LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM
EITHER SIDE OF THIS FRONT. TO THE W OF THIS FRONT...FAIR WEATHER
CONDITIONS ARE OCCURRING...WHERE SUBSIDENCE AND STABLE
ATMOSPHERIC CONDITIONS ARE PRESENT IN THE VICINITY OF A SURFACE
RIDGE. THIS SURFACE RIDGE EXTENDS SOUTHWESTWARD FROM A 1032 MB
SURFACE HIGH OVER THE W ATLC NEAR 37N73W. ALSO...ACROSS
LOCATIONS IN THE CENTRAL AND E ATLC THAT ARE SE OF THE
STATIONARY AND COLD FRONTS...SUBSIDENCE ASSOCIATED WITH A
SURFACE RIDGE IS SUPPORTING FAIR WEATHER CONDITIONS. HOWEVER...A
DEEP LAYER TROUGH IS PRESENT OVER THE E ATLC N OF 22N E OF 27W
WITH AN UPPER LOW NEAR 32N18W. THE DEEP LAYER TROUGH AND UPPER
LOW ARE ASSOCIATED WITH A 1008 MB SURFACE LOW NEAR 30N21W...A
SURFACE STATIONARY FRONT EXTENDING FROM 20N22W TO THE CANARY
ISLANDS NEAR 28N16W TO 30N16W...A SURFACE OCCLUDED FRONT
EXTENDING FROM 30N16W TO 32N18W TO 32N22W TO 30N23W...AND A
SURFACE TROUGH EXTENDING FROM S MOROCCO NEAR 29N11W TO W MOROCCO
NEAR 31N9W. THE SURFACE LOW IS FORECAST TO MOVE SOUTHEASTWARD
DURING THE NEXT DAY AND BE LOCATED NEAR 26N17W AS A 1012 MB
SURFACE LOW AT 27/0000 UTC. LOW LEVEL CONVERGENCE AND
ATMOSPHERIC INSTABILITY IN THE VICINITY OF THE SURFACE
LOW...SURFACE STATIONARY FRONT...SURFACE OCCLUDED FRONT...AND
SURFACE TROUGH ARE SUPPORTING SCATTERED SHOWERS N OF 27N E OF
26W. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL RIDGE IS S OF 7N
E OF 48W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS UPPER
LEVEL RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE
ITCZ. THIS UPPER LEVEL DIVERGENCE IS ALSO SUPPORTING SCATTERED
SHOWERS AND THUNDERSTORMS FROM 1N-4N BETWEEN 2W-5W.

$$
COHEN




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