000
AXNT20 KNHC 122348
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU JUL 12 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
SECTIONS OF SOUTH AMERICA...AND THE 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...
A HIGH AMPLITUDE TROPICAL WAVE IS ALONG 39W S OF 17N MOVING W 
15-20 KT.  BROAD LOW LEVEL INVERTED-V SHAPE PATTERN IS OBSERVED 
ON SATELLITE IMAGERY.  SCATTERED SHOWERS ARE FROM 6N-16N BETWEEN 
37W-42W.  A NEW SURGE OF AFRICAN DUST IS BEHIND THE WAVE AXIS TO 
10W.  AN OLDER SURGE OF AFRICAN DUST IS AHEAD OF THE WAVE AXIS 
TO BEYOND THE CARIBBEAN SEA S OF 22N.   

A TROPICAL WAVE IN THE CARIBBEAN SEA IS ALONG 71W/72W MOVING W 
AT 20 KT.  THE SAHARAN AIR LAYER PRODUCT FROM CIMSS IS SHOWING A 
PATCH OF AFRICAN DUST BEHIND THE WAVE AXIS COVERING THE EASTERN 
CARIBBEAN AND THE LESSER ANTILLES WITH HAZY CONDITIONS.  NO 
SIGNIFICANT CONVECTION IS NOTED.    

A TROPICAL WAVE IN THE CARIBBEAN SEA IS ALONG 80W/81W MOVING W 
15-20 KT.  AN AREA OF SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS OVER THE SW CARIBBEAN AND SURROUNDING COUNTRIES 
FROM 8N-14N BETWEEN 80W-85W.    

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N15W 8N25W 9N39W 4N51W.  BESIDES 
FOR CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...ISOLATED 
MODERATE CONVECTION IS FROM 5N-10N BETWEEN 42W-50W.  
 
...DISCUSSION...
GULF OF MEXICO...
1022 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 27N92W 
PRODUCING MAINLY FAIR WEATHER AND LIGHT ANTICYCLONIC SURFACE 
WINDS.  A SURFACE TROUGH IS OVER N FLORIDA AND THE NE GULF OF 
MEXICO ALONG 30N83W 28N87W.  SCATTERED SHOWERS REMAIN WITHIN 60 
NM OF THE TROUGH AXIS.  ELSEWHERE...SCATTERED MODERATE 
CONVECTION IS INLAND OVER CENTRAL AND SOUTHERN FLORIDA FROM 
25N-28N BETWEEN 80W-82W.  IN THE UPPER LEVELS...AN UPPER LEVEL 
LOW IS CENTERED OVER S MEXICO NEAR 24N104W.  AN UPPER LEVEL HIGH 
IS CENTERED OVER E TEXAS NEAR 32N98W.  ANOTHER UPPER LEVEL HIGH 
IS OVER THE CENTRAL GULF OF MEXICO NEAR 26N92W.  EXPECT THE 
SURFACE HIGH TO REMAIN STATIONARY WITH CONVECTION OVER THE N 
GULF STATES AND THE NE GULF OF MEXICO OVER THE NEXT 24 HOURS.  

CARIBBEAN SEA...
TWO TROPICAL WAVES ARE INFLUENCING THE WEATHER IN THE CARIBBEAN 
SEA.  SEE ABOVE.  TRADEWINDS ARE ALSO THE STRONGEST NEAR THE 
COAST OF N COLOMBIA AT 25-30 KT.  ELSEWHERE... SCATTERED 
MODERATE CONVECTION IS OVER CUBA BETWEEN 76W-84W.  SHOWERS 
EXTEND FROM THE VIRGIN ISLANDS TO HISPANIOLA ...AS NOTED ON THE 
SAN JUAN DOPPLER RADAR.  IN THE UPPER LEVELS... AN UPPER LEVEL 
HIGH IS OVER THE CENTRAL CARIBBEAN SEA NEAR 13N74W.  ANOTHER 
UPPER LEVEL HIGH IS OVER THE WINDWARD ISLANDS NEAR 13N59W.  
EXPECT SOME SHOWERS AND THUNDERSTORMS WITH THE TROPICAL WAVES 
DURING THE NEXT 24 HOURS.    

ATLANTIC OCEAN...
PREFRONTAL ACTIVITY IS PRODUCING ISOLATED MODERATE CONVECTION 
OVER THE W ATLANTIC FROM 30N-32N BETWEEN 75W-82W.  A DOMINATE 
1028 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 34N47W 
PRODUCING FAIR WEATHER OVER MOST OF THE ATLANTIC.  A SURFACE 
RIDGE EXTENDS W TO THE BAHAMAS NEAR 26N77W.  IN THE UPPER 
LEVELS... A RIDGE IS OVER THE W ATLANTIC N OF 20N W OF 65W.  AN 
UPPER LEVEL LOW IS OVER THE CENTRAL ATLANTIC NEAR 28N56W.  AN 
UPPER LEVEL HIGH IS OVER THE E ATLANTIC NEAR 18N33W.  
ANTICYCLONIC FLOW IS FROM 5N-30N E OF 40W.  

$$
FORMOSA