000
AXNT20 KNHC 220006
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT JUL 21 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...
TROPICAL WAVE IS OFF THE COAST OF W AFRICA ALONG 20W/21W S OF 
17N MOVING W 15 KT.  WELL DEFINED LOW TO MID LEVEL CYCLONIC 
ROTATION IS NOTED WITH CONVECTION CONFINED TO THE ITCZ.  
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE 
FROM 9N-11N BETWEEN 19W-23W. 

TROPICAL WAVE IS APPROACHING THE ERN CARIBBEAN ALONG 54W S OF 
22N MOVING W 15 KT.  BROAD LOW LEVEL INVERTED-V SIGNATURE IS 
NOTED WITH NO ASSOCIATED DEEP CONVECTION.  ISOLATED SHOWERS ARE 
FROM 14N-18N BETWEEN 53W-60W.  

TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 76W/77W S OF 20N 
MOVING W 15 KT.  AGAIN A BROAD LOW LEVEL INVERTED-V SIGNATURE IS 
NOTED WITH WIDELY SCATTERED MODERATE CONVECTION PERSISTING OVER 
JAMAICA AND ERN CUBA FROM 16N-23N BETWEEN 73W-78W.  

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N21W 7N30W 13N50W 10N63W. CLUSTERS 
OF SCATTERED MODERATE CONVECTION ARE FROM 5N-10N BETWEEN 
19W-31W. 
 
...DISCUSSION...
GULF OF MEXICO...
A 1019 MB HIGH IS CENTERED ALONG THE COAST OF LOUISIANA NEAR 
29N92W.  LIGHT ANTICYCLONIC WINDS ARE OVER THE GULF OF MEXICO.   
A PREFRONTAL SURFACE TROUGH IS OVER THE W ATLANTIC AND CENTRAL 
FLORIDA ALONG 30N77W 27N84W.  SCATTERED MODERATE CONVECTION IS 
FROM 25N-30N BETWEEN 79W-85W.  ELSEWHERE...SCATTERED MODERATE 
CONVECTION IS INLAND OVER THE YUCATAN PENINSULA FROM 19N-21N 
BETWEEN 87W-91W.  SCATTERED MODERATE TO STRONG CONVECTION IS 
INLAND OVER S MEXICO FROM 17N-18N BETWEEN 91W-95W.  WIDELY 
SCATTERED MODERATE CONVECTION IS INLAND OVER CUBA BETWEEN 
80W-83W.  IN THE UPPER LEVELS...THE E SIDE OF A RIDGE IS 
PRODUCING NLY UPPER LEVEL FLOW OVER THE W GULF OF MEXICO W OF 
90W.  A SMALL UPPER LEVEL LOW IS CENTERED OVER THE SE GULF NEAR 
23N86W.  EXPECT THE SURFACE HIGH TO FINALLY DISSIPATE OVER THE 
GULF DURING THE NEXT 24 HOURS.  ALSO EXPECT CONTINUED CONVECTION 
OVER THE ERN GULF...TO INCLUDE FLORIDA AND CUBA...FOR THE NEXT 
24 HOURS.      

CARIBBEAN SEA...
A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN SEA PRODUCING 
CONVECTION IN THE AREA. SEE ABOVE.  TRADEWINDS HAVE LIGHTENED TO 
15-20 KT ALONG THE COAST OF N COLOMBIA.  WIDELY SCATTERED 
MODERATE CONVECTION IS INLAND OVER CENTRAL AMERICA FROM PANAMA 
TO HONDURAS BETWEEN 77W-87W.  ELSEWHERE...SCATTERED MODERATE TO 
STRONG CONVECTION IS OVER HISPANIOLA FROM 18N-20N BETWEEN 
69W-72W.  IN THE UPPER LEVELS...THE UPPER LEVEL LOW OVER THE SE 
GULF OF MEXICO IS PRODUCING SWLY FLOW OVER THE NE CARIBBEAN SEA. 
AN UPPER LEVEL HIGH IS CENTERED OFF THE COAST OF N COLOMBIA NEAR 
13N76W.  ANOTHER UPPER LEVEL HIGH IS CENTERED N OF HISPANIOLA 
NEAR 21N70W.  EXPECT CONVECTION OVER THE WRN CARIBBEAN SEA AND 
CENTRAL AMERICA W OF 77W DURING THE NEXT 24 HOURS DUE TO A 
TROPICAL WAVE.  ALSO EXPECT CONVECTION OVER THE ERN CARIBBEAN 
SEA E OF 68W DUE TO ANOTHER TROPICAL WAVE.  

ATLANTIC OCEAN...
ONE DOMINATE 1035 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 
38N43N PRODUCING MAINLY FAIR WEATHER.  IN THE UPPER LEVELS... A 
WELL DEFINED UPPER LEVEL LOW IS NEAR 30N67W.  UPPER LEVEL 
DIFFLUENCE FROM THIS CENTER IS PRODUCING ISOLATED MODERATE 
CONVECTION FROM 21N-30N BETWEEN 56W-70W.  ANOTHER UPPER LEVEL 
LOW IS OVER THE E ATLANTIC NEAR 30N36W.  AN UPPER LEVEL HIGH IS 
OVER THE E ATLANTIC NEAR 22N17W.

$$
FORMOSA