[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091748
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT MAY 09 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N9W 3N17W 1N24W CROSSING THE
EQUATOR NEAR 28W EXTENDING TO 1S36W AND INTO NE BRAZIL NEAR
3S42W. NUMEROUS MODERATE CONVECTION IS FROM 4N-6N BETWEEN
9W-14W. SCATTERED MODERATE CONVECTION IS FROM 1N-5N BETWEEN
21W-28W. SCATTERED MODERATE CONVECTION IS ALSO S OF 2N BETWEEN
41W-51W INCLUDING THE COAST OF NE BRAZIL.

...DISCUSSION...

GULF OF MEXICO...
SUBSIDENCE IN NORTHERLY FLOW ALOFT AND DEEP LAYER DRY AIR ARE
PRESENT ACROSS MUCH OF THE GULF REGION. THIS SUBSIDENCE IS BEING
SUPPORTED BY A SURFACE RIDGE OVER THE N GULF THAT EXTENDS
WESTWARD FROM A SURFACE HIGH OVER THE CENTRAL ATLC. THE
SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS ARE RESULTING IN
GENERALLY FAIR WEATHER CONDITIONS ACROSS MUCH OF THE GULF
REGION. HOWEVER...UPPER LEVEL MOISTURE CONTINUES MOVING
SOUTHWARD ACROSS THE FAR N GULF...WHERE HIGH LEVEL CLOUD
COVERAGE IS INCREASING. THE RETURN FLOW AROUND THE
AFOREMENTIONED SURFACE HIGH AND SURFACE RIDGE IS RESULTING IN
SE SURFACE WINDS ACROSS THE GULF...WITH WIND SPEEDS UP TO 20 KT
ACROSS PORTIONS OF THE W AND MIDDLE GULF.

CARIBBEAN SEA...
A SURFACE HIGH OVER THE CENTRAL ATLC AND AN ASSOCIATED SURFACE
RIDGE N OF THE CARIBBEAN ARE RESULTING IN FRESH TRADE WINDS
ACROSS THE CARIBBEAN SEA. THESE FRESH TRADE WINDS ARE FORECAST
TO PERSIST ACROSS THE CARIBBEAN SEA INTO THE MIDDLE OF NEXT
WEEK. THE STRONGEST WINDS ARE FOUND NEAR THE COAST OF
COLOMBIA...WHERE NE TO E WINDS OF 20 TO 25 KT ARE OCCURRING. THE
TRADE WINDS ARE ADVECTING POCKETS OF LOW LEVEL MOISTURE WITH
ISOLATED SHOWERS WESTWARD ACROSS THE CARIBBEAN. THE GREATEST
CONCENTRATION OF THESE SHOWERS IS N OF 16N BETWEEN 64W-71W
INCLUDING PORTIONS OF HISPANIOLA AND PUERTO RICO. ALSO...A BROAD
UPPER LEVEL RIDGE IS PRESENT ACROSS THE CARIBBEAN SEA.
ATMOSPHERIC STABILITY ASSOCIATED WITH THIS RIDGE IS RESULTING IN
GENERALLY FAIR WEATHER CONDITIONS ACROSS MUCH OF THE CARIBBEAN.
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER LEVEL RIDGE IS
RESULTING IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE SW CARIBBEAN S OF 11N BETWEEN 78W-82W INCLUDING PORTIONS OF
PANAMA. ALSO...UPPER LEVEL MOISTURE AND HIGH LEVEL CLOUDS
CONTINUE TO STREAM NORTHEASTWARD ACROSS THE E AND S CARIBBEAN.

ATLANTIC OCEAN...
A SURFACE RIDGE ASSOCIATED WITH A 1028 MB SURFACE HIGH OVER THE
CENTRAL ATLC NEAR 32N49W IS AFFECTING MUCH OF THE ATLC PORTION
OF THE DISCUSSION AREA. THE SURFACE HIGH IS FORECAST TO MOVE
SOUTHWARD DURING THE NEXT DAY AND BE LOCATED NEAR 31N49W AS A
1026 MB SURFACE HIGH AT 10/1200 UTC. SUBSIDENCE ASSOCIATED WITH
THE SURFACE HIGH AND SURFACE RIDGE ARE RESULTING IN GENERALLY
FAIR WEATHER CONDITIONS ACROSS MUCH OF THE ATLC PORTION OF THE
DISCUSSION AREA. HOWEVER...POCKETS OF LOW LEVEL MOISTURE WITH
ISOLATED SHOWERS ARE MOVING WESTWARD ACROSS PORTIONS OF THE
SW NORTH ATLC...WITH THE GREATEST OF THESE SHOWERS S OF 23N
BETWEEN 64W-71W INCLUDING PORTIONS OF HISPANIOLA AND PUERTO
RICO. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL RIDGE IS PRESENT
S OF 12N E OF 60W...WITH AN UPPER LEVEL HIGH NEAR 7N43W. UPPER
LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER LEVEL RIDGE AND UPPER
LEVEL HIGH IS ENHANCING THE CONVECTION ASSOCIATED WITH THE
ITCZ. ALSO...UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER
LEVEL HIGH NEAR 7N43W SUPPORTED THE RECENT CONVECTION AND RECENT
MAJOR FLOODING ACROSS PORTIONS OF NE BRAZIL. THE GREATEST
CONCENTRATION OF CONVECTION OVER BRAZIL IS NOW LOCATED OVER
WESTERN PORTIONS OF BRAZIL...THOUGH SCATTERED MODERATE
CONVECTION ASSOCIATED WITH THE ITCZ IS AFFECTING THE COAST OF NE
BRAZIL.

$$
COHEN


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