000
AXNT20 KNHC 120523
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI JUN 12 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.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 16N52W TO 3N55W MOVING W NEAR 15 KT. WAVE 
REMAINS IN AN UPPER DIFFLUENT ZONE BUT THE CONVECTION IS WEAKENING. 
SCATTERED MODERATE CONVECTION IS WITHIN 180 NM W OF THE WAVE AXIS.   

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 8N12W 6N21W 3N33W 2N38W 1N51W. 
SCATTERED/NUMEROUS STRONG CONVECTION IS FROM 5N-10N BETWEEN 10W-14W 
INCLUDING ALL OF SIERRA LEONE. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS INLAND AND WITHIN 60 NM ALONG THE COAST OF SW AFRICA 
BETWEEN THE PRIME MERIDIAN AND 5W. SMALL CLUSTERS OF SIMILAR 
CONVECTION ARE WITHIN 90 NM S OF THE ITCZ AXIS FROM 14W-21W AND S OF 
THE EQUATOR TO JUST OFF THE COAST OF E BRAZIL BETWEEN 38W-46W. 
SCATTERED MODERATE CONVECTION IS WITHIN 75/90 NM ALONG THE ITCZ AXIS 
FROM 22W-27W. 

...DISCUSSION...

GULF OF MEXICO...
A 1015 MB HIGH REMAINS NEARLY STATIONARY OVER THE NE GULF NEAR 
28N88W KEEPING WINDS LIGHT ACROSS THE GULF. AFTERNOON THUNDERSTORMS 
THAT DEVELOPED OVER SW FLORIDA HAVE AGAIN TONIGHT PUSHED S INTO THE 
FLORIDA STRAITS AND OVER THE FLORIDA KEYS WHILE THE REMAINDER OF THE 
GULF IS DOMINATED BY FAIR WEATHER WITH HIGH DEBRIS CLOUDS MOVING OFF 
TEXAN AND THE FAR NE MEXICAN COASTS. THE BROAD UPPER RIDGE REMAINS 
ANCHORED OVER CENTRAL MEXICO DOMINATING THE UPPER PATTERN OVER THE 
GULF. LITTLE CHANGE IN THIS PATTERN IS EXPECTED OVER THE NEXT DAY OR 
TWO...SO MAINLY FAIR WEATHER IS FORECAST TO PERSIST. 

CARIBBEAN SEA...
A SURFACE TROUGH REMAINS IN THE W CARIBBEAN EXTENDING FROM 18N80W TO 
THE COAST OF PANAMA NEAR 9N81W. HOWEVER...THE ACTIVITY IN THE 
CARIBBEAN IS DUE TO UPPER LEVEL FEATURES. AN UPPER TROUGH EXTENDS 
FROM THE W ATLC ACROSS CUBA OVER THE NW CARIBBEAN INTO CENTRAL 
AMERICA. A BROAD UPPER RIDGE DOMINATES THE REMAINDER OF THE 
CARIBBEAN DRAWING UPPER LEVEL MOSITURE OVER THE CENTRAL CARIBBEAN 
AND PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS MAINLY N OF 16N ACROSS HISPANIOLA BETWEEN 
70W-77W WITH SCATTERED SHOWERS S OF 16N BETWEEN 67W-76W AND S OF 14N 
W OF 76W TO INLAND OVER CENTRAL AND SOUTH AMERICA. A TROPICAL WAVE 
IS EXPECTED TO MOVE INTO THE E CARIBBEAN ON SAT. 

ATLANTIC OCEAN...
A SURFACE TROUGH IS MOVING N OVER THE W ATLC EXTENDING FROM 30N67W 
TO 29N73W ROTATING AROUND A SURFACE RIDGE THAT DOMINATES THE ATLC. 
AN UPPER TROUGH EXTENDS ACROSS THE FAR W ATLC ACROSS CUBA INTO THE 
NW CARIBBEAN W OF 73W TO THE FLORIDA PENINSULA. THE BROAD UPPER 
RIDGE FROM THE CARIBBEAN EXTENDS OVER THE REMAINDER OF THE W ATLC 
INTO THE CENTRAL ATLC PROVIDING DIFFLUENCE ALOFT AND GENERATING 
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 30N TO 
OVER THE GREATER ANTILLES BETWEEN 63W-73W. A BROAD SURFACE RIDGE 
DOMINATES THE REMAINDER OF THE ATLC ANCHORED BY A 1025 MB HIGH NEAR 
29N38W GIVING THE MOST OF THE REMAINDER OF THE AREA FAIR WEATHER 
TONIGHT. THE ONLY EXCEPTION IS SOME MID/HIGH CLOUDS ALONG THE 
WESTERN EDGE OF AN UPPER RIDGE THAT EXTENDS ALONG 13N FROM AFRICA TO 
44W. 

$$
WALLACE