000
AXNT20 KNHC 061739
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI JUL 06 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS FROM 23N41W TO 14N39W MOVING W 15-20 KT. WAVE 
IS ALONG THE LEADING EDGE OF A MOISTURE SURGE AS DEPICTED ON THE 
TOTAL PRECIPITABLE WATER IMAGERY WHICH COINCIDES WITH THE 
LEADING EDGE OF A PLUM OF SAHARAN DUST. THUS...NO ASSOCIATED 
CONVECTION. 

TROPICAL WAVE IS FROM 23N75W ACROSS CUBA TO 13N81W MOVING W NEAR 
20 KT. WAVE IS EMBEDDED WITHIN A MOISTURE SURGE AS DEPICTED ON 
THE TOTAL PRECIPITABLE WATER IMAGERY. AN UPPER RIDGE IS JUST TO 
THE E OF THE TROPICAL WAVE AND IS PROVIDING DIFFLUENCE ALOFT TO 
ENHANCE SCATTERED SHOWERS/THUNDERSTORMS FROM 16N-20N BETWEEN 
75W-82W INCLUDING JAMAICA AND THE CAYMAN ISLANDS. 

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL 
ATLC NEAR 19N16W ALONG 12N24W TO 9N36W WHERE THE ITCZ AXIS 
CONTINUES ALONG 8N48W TO INLAND OVER SOUTH AMERICA NEAR 7N59W. 
CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM 6N-12N E OF 
25W TO INLAND OVER AFRICA AND FROM 6N-10N BETWEEN 32W-36W. 

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE CONTINUES TO DOMINATE THE GULF THIS AFTERNOON 
ANCHORED BY A 1019 MB HIGH AT 06/1500 UTC NEAR 27N89W. AN E/W 
ELONGATED UPPER LOW IS CENTERED OVER ANDROS ISLAND IN THE W ATLC 
WITH A TROUGH AXIS EXTENDING INTO THE GULF OVER W CUBA TO 23N88W 
GENERATING ISOLATED SHOWERS/THUNDERSTORMS FROM 22N-26N E OF 88W 
TO OVER THE FLORIDA KEYS AND THE STRAITS OF FLORIDA. AN UPPER 
RIDGE EXTENDS ACROSS THE N GULF N OF 27N WITH A WEAK INVERTED 
UPPER LEVEL TROUGH EXTENDING FROM FROM NE FLORIDA TO NEAR MOBILE 
ALABAMA. THIS UPPER TROUGH IS GENERATING SCATTERED TO HEAVY 
SHOWERS WITH EMBEDDED THUNDERSTORMS N OF 28N TO INLAND OVER W 
FLORIDA AND S ALABAMA BETWEEN 86W-89W. ISOLATED SHOWERS ARE 
POSSIBLE ACROSS THE REMAINDER OF THE GULF THIS AFTERNOON. 
SURFACE RIDGE WILL REMAIN THROUGH TUE.

CARIBBEAN SEA...
THE MAIN TWO FEATURES IN THE CARIBBEAN CONTINUE TO BE THE 
TROPICAL WAVE AND MONSOON TROUGH THIS AFTERNOON. THE TROPICAL 
WAVE IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS FROM 16N-20N 
BETWEEN 75W-83W INCLUDING JAMAICA AND THE CAYMAN ISLANDS. THE 
MONSOON TROUGH EXTENDS FROM A 1007 MB LOW ALONG THE COAST OF 
COLOMBIA NEAR 9N76W ACROSS COSTA RICA INTO THE E PACIFIC REGION 
GENERATING SCATTERED TO HEAVY SHOWERS/SCATTERED THUNDERSTORMS S 
OF 11N TO INLAND OVER PANAMA BETWEEN 76W-82W AND FROM 11N-16N W 
OF 82W TO INLAND OVER NICARAGUA. THIS IS LEAVING THE REMAINDER 
OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS AFTERNOON. 
TROPICAL WAVE WILL MOVE W ACROSS NW CARIBBEAN THROUGH SAT THEN 
OVER THE YUCATAN PENINSULA SAT NIGHT. A SECOND TROPICAL WAVE 
WILL REACH THE E CARIBBEAN SUN NIGHT AND INTO CENTRAL CARIBBEAN 
TUE.

ATLANTIC OCEAN...
AN E/W ELONGATED UPPER LOW IS CENTERED OVER ANDROS ISLAND IN THE 
W ATLC WITH A TROUGH AXIS EXTENDING INTO THE GULF OF MEXICO 
THROUGH THE STRAITS OF FLORIDA. AN UPPER RIDGE OVER THE SW ATLC 
ANCHORED N OF PUERTO RICO NEAR 22N65W IS PROVIDING DIFFLUENCE 
ALOFT TO GENERATE SCATTERED SHOWERS/THUNDERSTORMS WITHIN 90/120 
NM OF LINE FROM 25N70W TO THE COAST OF CUBA NEAR 22N77W. THE 
ATLC BASIN IS DOMINATED BY A LARGE SURFACE RIDGE ANCHORED BY A 
1031 MB HIGH NW OF THE AZORES AND A RIDGE AXIS EXTENDING THROUGH 
32N48W ALONG 28N66W ACROSS CENTRAL FLORIDA INTO THE GULF OF 
MEXICO AND IS ENJOYING FAIR WEATHER THIS AFTERNOON. A PLUM OF 
SAHARAN DUST CONTINUES TO SPREAD W BETWEEN 10N-28N TO 42W. 
SURFACE RIDGE WILL REMAIN THROUGH TUE. 

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
PAW