000
AXNT20 KNHC 211807
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI APR 21 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 
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...WEATHER OBSERVATIONS... 
RADAR...AND METEOROLOGICAL ANALYSIS.

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

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N10W 4N20W 1N30W EQ40W 2S45W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALONG THE 
COAST OF W AFRICA FROM EQ-6N BETWEEN THE PRIME MERIDIAN AND 4W.  
SCATTERED MODERATE CONVECTION IS FROM 3N-5N BETWEEN 12W-14W... 
AND FROM 2N-5N BETWEEN 31W-37W.  WIDELY SCATTERED MODERATE 
CONVECTION IS FROM EQ-2N BETWEEN 38W-46W.    

...DISCUSSION...
GULF OF MEXICO...
10-15 KT SE RETURN FLOW DOMINATES THE GULF OF MEXICO DUE TO A 
1022 MB HIGH OVER THE W ATLANTIC.  A 1011 MB LOW IS OVER S 
ARKANSAS.  A COLD FRONT EXTENDS SW FROM THE LOW TO S TEXAS NEAR 
29N100W.  PREFRONTAL SCATTERED MODERATE CONVECTION IS NOTED OVER 
LOUISIANA AND ITS COASTAL WATERS FROM 29N-34W BETWEEN 90W-93W.  
THE REMAINDER OF THE GULF OF MEXICO HAS WARM FAIR WEATHER.  IN 
THE UPPER LEVELS... MOSTLY WLY ZONAL FLOW DOMINATES THE GULF.  
STRONG SUBSIDENCE COVERS THE GULF EXCEPT OVER LOUISIANA AND ITS 
COASTAL WATERS.  EXPECT THE TAIL END OF THE COLD FRONT TO EXTEND 
FROM TALLAHASSEE FLORIDA TO 27N90W SATURDAY MORNING WITH 
CONVECTION.     

CARIBBEAN SEA...
15-25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA.  SCATTERED 
SHOWERS ARE OVER THE LEEWARD ISLANDS N OF 17N AND E OF 70W TO 
INCLUDE THE DOMINICAN REPUBLIC...PUERTO RICO...AND THE VIRGIN 
ISLANDS.  SAN JUAN RADAR DEPICTS THE SHOWERS WELL.  MORE 
SCATTERED SHOWERS ARE OVER COASTAL REGIONS OF CENTRAL AMERICA 
FROM PANAMA TO HONDURAS MOVING INLAND TO 85W.  IN THE UPPER 
LEVELS... WLY ZONAL FLOW WITH STRONG SUBSIDENCE PREVAILS 
THROUGHOUT THE CARIBBEAN SEA.  EXPECT SCATTERED SHOWERS TO 
CONTINUE OVER HISPANIOLA AND PUERTO RICO...AS WELL AS OVER 
CENTRAL AMERICA E OF 85W...FOR THE NEXT 24 HOURS.       

ATLANTIC OCEAN...
1022 MB HIGH IS OVER THE W ATLANTIC NEAR 31N73W.  THE TAIL END 
OF A DISSIPATING COLD FRONT IS OVER THE CENTRAL ATLANTIC ALONG 
32N50W 26N57W.  SCATTERED SHOWERS ARE WITHIN 60 NM OF THE 
FRONT.  A 1030 MB HIGH IS OVER THE E ATLANTIC NEAR 34N33W.  A 
SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 23N50W.  IN THE 
UPPER LEVELS... A TROUGH IS N OF 20N BETWEEN 50W-70W.  A RIDGE 
IS N OF 20N BETWEEN 30W-50W.  A TROUGH IS N OF 20N BETWEEN 
10W-30W.  WLY ZONAL FLOW IS FROM 10N-20N BETWEEN 10W-60W.  ELY 
FLOW IS OVER THE TROPICS FROM EQ-10N BETWEEN 10W-50W.  EXPECT 
THE DISSIPATING COLD FRONT TO BE A TROUGH ALONG 45W SATURDAY 
MORNING.      

$$
FORMOSA