000
AXNT20 KNHC 180623
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SAT MAR 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N8W 4N20W 3N30W 4N40W 4N50W. 
WEAKENING SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 75 NM 
OF THE AXIS BETWEEN 14W-20W.
 
...DISCUSSION...

GULF OF MEXICO...
AS OF 0300 UTC...1019 MB HIGH IS CENTERED OVER THE NE GULF OF 
MEXICO NEAR 28N88W.  RETURN SW FLOW IS PRODUCING WIDELY 
SCATTERED MODERATE CONVECTION ALONG THE SLOPES OF THE SIERRA 
MADRE MOUNTAINS AND THE MEXICAN COAST FROM 21N-26N BETWEEN 
95W-100W.  SLY RETURN FLOW OVER E TEXAS AND S LOUISIANA IS 
PRODUCING A WARM FRONT ALONG 29N98W 30N94W 29N90W.  THE TAIL END 
OF A COLD FRONT IS OVER N FLORIDA ALONG 29N80W 29N83W.  NO 
CONVECTION IS ALONG THE FRONT.  SLIGHT TEMPERATURE CHANGES ARE 
ON EACH SIDE OF THE FRONT.  IN THE UPPER LEVELS... A BROAD RIDGE 
IS OVER THE GULF PRODUCING MOSTLY WLY FLOW.  PACIFIC MOISTURE IS 
OVER MEXICO AND THE CENTRAL GULF BETWEEN 22N-27N.  EXPECT...THE 
SURFACE HIGH TO STAY STATIONARY FOR THE NEXT 24 HOURS AND THUS 
CONTINUE THE RETURN FLOW OVER THE W GULF.  THE WARM FRONT WILL 
MOVE FURTHER N INTO TEXAS.  THE COLD FRONT OVER FLORIDA WILL 
MOVE DOWN TO S FLORIDA WITH NO CONVECTION AND LITTLE TEMPERATURE 
CHANGE.   

CARIBBEAN SEA...
NOCTURNAL THUNDERSTORMS ARE INLAND OVER N COLOMBIA FROM 8N-11N 
BETWEEN 73W-75W MOVING NE WITH UPPER LEVEL STEERING.  15-20 KT 
TRADES ARE OVER THE CARIBBEAN SEA.  PATCHES OF BROKEN LOW CLOUDS 
AND SCATTERED SHOWERS ARE OVER PORTIONS OF THE LEEWARD ISLANDS 
TO INCLUDE PUERTO RICO AND HISPANIOLA.  IN THE UPPER LEVELS...
A SMALL TROUGH IS OVER THE W CARIBBEAN W OF 75W.  A RIDGE IS 
OVER THE REMAINDER OF THE SEA PRODUCING SW FLOW.  A GOOD AMOUNT 
OF UPPER LEVEL MOISTURE IS OVER COLOMBIA WHILE STRONG SUBSIDENCE 
IS OVER THE CARIBBEAN SEA.  EXPECT...THE UPPER AIR PATTERN TO 
SHIFT E OVER THE NEXT 24 HOURS WITH NO CHANGE IN THE SURFACE 
TRADES.  THE BEST CHANCE OF SHOWERS WILL BE OVER THE WINDWARD 
AND LEEWARD ISLANDS.  

ATLANTIC OCEAN...
COLD FRONT ID OVER THE W ATLANTIC ALONG 32N74W 29N80W.  ISOLATED 
SHOWERS ARE ALONG THE FRONT BETWEEN 75W-77W.  A PREFRONTAL 
TROUGH EXTENDS FROM 30N72W TO THE BAHAMAS NEAR 25N78W.  
SCATTERED SHOWERS ARE WITHIN 30 NM OF THE TROUGH.  A 1021 MB 
HIGH IS OVER THE CENTRAL ATLANTIC NEAR 29N55W.  A WEAK 
STATIONARY FRONT IS ALONG 32N40W 27N50W 25N65W.  BROKEN LOW 
CLOUDS AND SCATTERED SHOWERS ARE WITHIN 90 NM OF THE FRONT.  A 
1021 MB HIGH IS FURTHER E AT 26N43W.  A SURFACE LOW W OF 
PORTUGAL EXTENDS A SURFACE TROUGH TO NEAR THE CANARY ISLANDS.  
AN AREA OF AFRICAN DUST THAT CONTINUES TO SLOWLY THIN...REMAINS  
OVER THE TROPICAL ATLANTIC.  THE DUST EXTENDS FROM THE ITCZ 
NORTHWARD TO 20N E OF ABOUT 52W. IT DOES NOT APPEAR THAT THE 
DUST IS RESTRICTING SURFACE VISIBILITIES ACROSS THE TROPICAL 
ATLC OR EAST CARIBBEAN.  IN THE UPPER LEVELS...MOSTLY WESTERLY 
ZONAL FLOW IS OVER THE ATLANTIC N OF 20N.  AN ANTICYCLONIC 
CIRCULATION IS CENTERED OVER THE TROPICS NEAR 5N40W.  BROAD 
ANTICYCLONIC FLOW IS FROM EQ-20N BETWEEN 20W-75W.  EXPECT THE 
STATIONARY FRONT TO CONTINUE TO WEAKEN AND DISSIPATE WITHIN THE 
NEXT 12-18 HOURS DUE TO LACK OF UPPER AIR SUPPORT.      

$$
FORMOSA