000
AXNT20 KNHC 131029
TWDAT 

 TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUN 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 63WW S OF 16N MOVING W 15 KT. WAVE REMAINS 
EMBEDDED WITHIN DRIER AIR AND HAS PASTED THE LESSER ANTILLES. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 75 NM OF 
LINE FROM THE TROUGH AXIS NEAR 13N63W ACROSS THE WINDWARD ISLANDS... 
TRINIDAD AND TOBAGO ALONG THE COAST OF VENEZUELA AND GUYANA TO 
7N57W. 

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N12W 6N23W 3N32W 2N38W 1N52W. 
SCATTERED/NUMEROUS STRONG CONVECTION IS WITHIN 45 NM OF THE ITCZ 
AXIS FROM 14W-16W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION 
ARE FROM 5N-10N BETWEEN 10W-17W INCLUDING THE COAST FROM N LIBERIA 
TO GUINEA. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 
4N-7N BETWEEN 21W-24W AND WITHIN 60 NM ALONG THE ITCZ AXIS FROM 
25W-29W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 5N TO 
THE ITCZ AXIS BETWEEN 29W-49W AND FROM 5N-8N BETWEEN 50W-57W. 

...DISCUSSION...

GULF OF MEXICO...
A 1017 MB HIGH REMAINS NEARLY STATIONARY OVER THE E GULF NEAR 
28N88W KEEPING WINDS LIGHT ACROSS THE AREA. THE GULF IS DOMINATED BY 
FAIR WEATHER AGAIN THIS MORNING WITH HIGH DEBRIS CLOUDS COVERING THE 
NW GULF N OF 23N W OF 88W AND SOME ISOLATED LOW LEVEL SHOWERS 
THROUGH THE FLORIDA STRAITS. THE BROAD UPPER RIDGE REMAINS ANCHORED 
OVER W/CENTRAL MEXICO DOMINATING THE UPPER PATTERN OVER THE GULF. 
LITTLE CHANGE IN THIS PATTERN IS EXPECTED OVER THE WEEKEND AND 
THROUGH THE FIRST OF NEXT WEEK. 

CARIBBEAN SEA...
THE SURFACE TROUGH THAT WAS IN THE W CARIBBEAN HAS WEAKEN 
SIGNIFICANTLY. HOWEVER...A SECOND BOUNDARY IS DEVELOPING TO THE E 
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120 NM E 
OF A LINE FROM THE CAYMAN ISLANDS NEAR 19N82W TO JUST OFF THE COAST 
OF PANAMA NEAR 10N78W. THE UPPER TROUGH FROM THE W ATLC EXTENDS 
ACROSS CUBA AND THE NW CARIBBEAN TO 14N W OF 77W TO INLAND OVER 
CENTRAL AMERICA AND THE YUCATAN SUPPORTING A SURFACE TROUGH JUST TO 
THE E THAT EXTENDS FROM THE TURKS AND CAICOS ACROSS THE E PENINSULAS 
OF HAITI TO 16N74W. 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 S OF 15N TO INLAND OVER COLOMBIA AND 
E PANAMA BETWEEN 70W-77W. SCATTERED SHOWERS ARE S OF 14N W OF 78W TO 
THE COAST OF COSTA RICA AND NICARAGUA. A TROPICAL WAVE IS GENERATING 
THE ACTIVITY OVER THE WINDWARD ISLANDS...SEE ABOVE. 

ATLANTIC OCEAN...
AN UPPER TROUGH EXTENDS FROM AN UPPER LOW IN THE W ATLC NEAR 27N72W 
ACROSS CUBA INTO THE NW CARIBBEAN GENERATING ISOLATED SHOWERS/ 
THUNDERSTORMS BETWEEN THE BAHAMAS AND CUBA W OF 76W TO THE FLORIDA 
STRAITS. THE BROAD UPPER RIDGE FROM THE CARIBBEAN EXTENDS OVER THE 
REMAINDER OF THE W/CENTRAL ATLC PROVIDING DIFFLUENCE ALOFT AND 
CONTINUES TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS WITHIN 150/200 NM OF LINE FROM OVER THE GREATER 
ANTILLES NEAR 20N73W TO ACROSS BERMUDA. A BROAD SURFACE RIDGE 
DOMINATES THE REMAINDER OF THE ATLC ANCHORED BY A 1024 MB HIGH 
CENTERED NEAR 28N53W. A STATIONARY FRONTAL BOUNDARY LIES ALONG 32N 
BETWEEN 31W-42W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS FROM THE FRONT TO 30N BETWEEN 35W-42W. THE REMAINDER 
OF THE AREA IS UNDER FAIR WEATHER AGAIN THIS MORNING.  

$$
WALLACE