[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 250949 CCA
TWDAT

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST WED FEB 25 2009

...CORRECTED GULF OF MEXICO AND ATLANTIC OCEAN SECTIONS...

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 1N17W CROSSING THE EQUATOR
NEAR 21W EXTENDING TO 2S33W INTO NE BRAZIL NEAR 2S46W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS S OF 5N BETWEEN
11W-20W. SCATTERED MODERATE CONVECTION IS S OF 1N BETWEEN
22W-30W. SCATTERED MODERATE CONVECTION IS ALSO S OF 3N BETWEEN
34W-49W.

...DISCUSSION...

GULF OF MEXICO...
GENERALLY FAIR WEATHER IS PRESENT ACROSS MUCH OF THE GULF
REGION...WHERE CONFLUENCE IN WESTERLY FLOW ALOFT IS SUPPORTING
ATMOSPHERIC SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS. DEEP
LAYER DRY AIR IS ALSO PRESENT ACROSS MUCH OF THE GULF REGION.
HOWEVER...UPPER LEVEL MOISTURE IS STREAMING SOUTHEASTWARD INTO
PORTIONS OF THE N GULF. THE SUBSIDENCE IS ALSO BEING SUPPORTED
IN THE VICINITY OF A SURFACE RIDGE OVER THE GULF THAT EXTENDS
SOUTHWESTWARD FROM A 1030 MB SURFACE HIGH OVER SE NORTH CAROLINA
NEAR 35N78W. ACROSS THE NW GULF...SE TO S SURFACE WINDS ARE
PRESENT AROUND THIS SURFACE RIDGE.

CARIBBEAN SEA...
A DEEP LAYER TROUGH OVER THE W ATLC EXTENDS INTO THE NW
CARIBBEAN AND IS ASSOCIATED WITH A DISSIPATING SURFACE COLD
FRONT IN THE NW CARIBBEAN THAT EXTENDS FROM 19N76W TO E CUBA
NEAR 20N75W. LOW LEVEL CONVERGENCE IS SUPPORTING ISOLATED
SHOWERS WITHIN 60 NM EITHER SIDE OF THIS FRONT. TRADE WINDS
ACROSS THE CARIBBEAN SEA ARE FORECAST TO WEAKEN THROUGH SUNDAY.
GENERALLY FAIR WEATHER CONDITIONS ARE OCCURRING ACROSS MUCH OF
THE CARIBBEAN REGION...WHERE A BROAD UPPER LEVEL RIDGE IS
PRESENT TO THE SE OF THE DEEP LAYER TROUGH OVER THE W ATLC AND
NW CARIBBEAN. 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-15N E OF 71W.

ATLANTIC OCEAN...
A DEEP LAYER TROUGH OVER THE W ATLC IS ASSOCIATED WITH A SURFACE
COLD FRONT THAT EXTENDS FROM E CUBA NEAR 20N75W TO 27N63W TO
32N55W TO NE OF THE DISCUSSION AREA. LOW LEVEL CONVERGENCE IS
SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE THIS
FRONT. THIS FRONT IS DISSIPATING W OF 72W. TO THE W OF THIS
FRONT...FAIR WEATHER CONDITIONS ARE PRESENT...WHERE SUBSIDENCE
AND STABLE ATMOSPHERIC CONDITIONS ARE OCCURRING IN THE VICINITY
OF A SURFACE RIDGE. THIS SURFACE RIDGE EXTENDS SOUTHEASTWARD
FROM A 1030 MB SURFACE HIGH OVER SE NORTH CAROLINA NEAR 35N78W.
ALSO...ACROSS LOCATIONS IN THE CENTRAL AND E ATLC THAT ARE SE OF
THE COLD FRONT...SUBSIDENCE ASSOCIATED WITH A SURFACE RIDGE IS
SUPPORTING FAIR WEATHER CONDITIONS. HOWEVER...A DEEP LAYER
TROUGH IS PRESENT OVER THE E ATLC N OF 21N E OF 29W WITH AN
UPPER LOW NEAR 30N20W. THE DEEP LAYER TROUGH AND UPPER LOW ARE
ASSOCIATED WITH A DISSIPATING SURFACE COLD FRONT THAT EXTENDS
FROM 21N33W TO 24N22W TO A 1010 MB SURFACE LOW W OF THE CANARY
ISLANDS NEAR 29N21W. THIS SURFACE LOW IS FORECAST TO REMAIN
NEARLY STATIONARY DURING THE NEXT DAY. ALSO...A 1010 MB SURFACE
LOW IS PRESENT NEAR 32N17W. THIS SURFACE LOW IS FORECAST TO MOVE
SOUTHWESTWARD DURING THE NEXT DAY AND MERGE WITH THE
AFOREMENTIONED 1010 MB SURFACE LOW W OF THE CANARY ISLANDS NEAR
29N21W...RESULTING IN A 1010 MB SURFACE LOW NEAR 29N21W AT
26/0000 UTC. LOW LEVEL CONVERGENCE AND ATMOSPHERIC INSTABILITY
IN THE VICINITY OF THE SURFACE LOWS AND DISSIPATING SURFACE COLD
FRONT ARE SUPPORTING SCATTERED SHOWERS N OF 25N BETWEEN 16W-25W.
ACROSS THE TROPICAL ATLC...AN UPPER RIDGE IS S OF 9N E OF 47W.
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS UPPER LEVEL RIDGE IS
ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ.

$$
COHEN




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