000
AXNT20 KNHC 161033
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUN 16 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 80W S OF 18N MOVING W NEAR 15 KT. LITTLE 
CONVECTION IS ASSOCIATED WITH THE WAVE. CURRENT POSITION IS BASED ON 
CONTINUITY. 

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 10N12W 9N20W 5N30W 3N40W AND INTO NE 
BRAZIL NEAR 1N52W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE 
WITHIN 90 NM N OF THE AXIS BETWEEN 18W-24W. LARGE CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150 NM ON 
EITHER SIDE OF THE AXIS BETWEEN 26W-39W. SIMILAR ACTIVITY IS WITHIN 
300 NM OF EITHER SIDE OF THE AXIS BETWEEN 39W-52W AND INLAND OVER NE 
SOUTH AMERICA.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE TROUGH IS OVER THE N FLORIDA PENINSULA EXTENDING FROM NEAR 
28N81W TO BEYOND 32N82W CONTINUING N TO A SURFACE LOW OVER THE SOUTH 
CAROLINA/GEORGIA BORDER. UPPER LEVEL DIFFLUENCE OVER THE YUCATAN 
PENINSULA IS SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS OVER 
THE YUCATAN PENINSULA AND THE E BAY OF CAMPECHE S OF 21N E OF 96W. 
ELSEWHERE...FAIR WEATHER PREVAILS AS A STATIONARY 1016 MB SURFACE 
HIGH LOCATED NEAR 28N87W DOMINATES THE REMAINDER OF THE GULF OF 
MEXICO. AN UPPER LEVEL RIDGE EXTENDING FROM MEXICO ACROSS THE GULF 
AND THE FLORIDA PENINSULA IS SUPPORTING THE SURFACE HIGH PROVIDING 
DRY AIR AND SUBSIDENCE. ANTICYCLONIC FLOW AROUND THE SURFACE HIGH IS 
AFFECTING MUCH OF THE GULF...WITH SE WINDS OF 15 TO 20 KT OCCURRING 
ACROSS PORTIONS OF THE FAR NW GULF W OF 95W. THE SURFACE HIGH IS 
FORECAST TO REMAIN OVER THE GULF AND A SURFACE TROUGH CURRENTLY OVER 
WESTERN CARIBBEAN IS EXPECTED TO MOVE ACROSS YUCATAN PENINSULA TODAY 
AND ACROSS BAY OF CAMPECHE GULF THROUGH WEDNESDAY.
 
CARIBBEAN SEA...
A SURFACE TROUGH IS IN THE NW CARIBBEAN EXTENDING FROM 21N86W TO 
16N87W TO INLAND OVER HONDURAS. LOW LEVEL CONVERGENCE ALONG WITH 
UPPER LEVEL DIFFLUENCE OVER THE YUCATAN PENINSULA ARE SUPPORTING 
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE W CARIBBEAN FROM 16N-20N 
W OF 81W TO INLAND OVER PORTIONS OF CENTRAL AMERICA AND FROM 20N-22N 
BETWEEN 79W-80W. ATMOSPHERIC INSTABILITY IS RESULTING IN ISOLATED 
SHOWERS/THUNDERSTORMS ACROSS HISPANIOLA AND THE ADJACENT COASTAL 
WATERS. SIMILAR ACTIVITY ACROSS THE LESSER ANTILLES E OF 66W IS 
SUPPORTED BY AN UPPER LEVEL TROUGH THAT EXTENDS FROM THE CENTRAL 
ATLC OVER THE FAR E CARIBBEAN.

ATLANTIC OCEAN...
UPPER LEVEL TROUGHING OVER THE NW ATLC N OF THE DISCUSSION AREA IS 
SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE W ATLC N OF 
31N BETWEEN 60W-71W. A BROAD UPPER TROUGH COVERS THE CENTRAL ATLC TO 
OVER THE FAR E CARIBBEAN WITH AN EMBEDDED UPPER LOW NEAR 29N50W 
SUPPORTING A WEAK SURFACE TROUGH THAT EXTENDS FROM 28N52W TO 31N49W. 
UPPER LEVEL DIFFLUENCE TO THE E OF THE UPPER LOW AND E OF THE 
SURFACE TROUGH IS GENERATING ISOLATED SHOWERS FROM 27N-30N BETWEEN 
47W-50W. AT THE BASE OF THE UPPER TROUGH ARE SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS FROM 11N-18N W OF 55W TO OVER THE LESSER 
ANTILLES. ELSEWHERE ACROSS THE ATLC...A BROAD SURFACE RIDGE ANCHORED 
BY A 1029 MB HIGH N OF THE DISCUSSION AREA NEAR 35N34W DOMINATES 
BRINGING FAIR WEATHER ACROSS THE REMAINDER OF THE ATLC.

$$
WALTON/WALLACE