000
AXNT20 KNHC 201808
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU APR 20 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 
1645 UTC.

...THE ITCZ...

THE ITCZ EXTENDS FROM WEST AFRICA AT 6N10W TO SOUTH AMERICA AT 
3S42W.  NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE OCCURRING 
IN THE GULF OF GUINEA ROUGHLY FROM 0N0W TO 2N10W TO 8N13W TO 
4N8W TO 5N1W. ISOLATED MODERATE SHOWERS WITH SOME THUNDERSTORMS 
ARE LOCATED WITHIN 30 NM OF A LINE EXTENDING FROM 7N13W TO 5N25W 
TO 0N43W.  NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE 
OCCURRING ALONG THE NORTHERNMOST COAST OF BRAZIL.

...DISCUSSION...

THE GULF OF MEXICO...AND THE ATLANTIC OCEAN
NORTH OF 20N WEST OF 60W...
THE MID TO UPPER LEVEL LOW CURRENTLY OVER NEW MEXICO IS 
PRODUCING 60 TO 90 KT WINDS OUT OF THE WEST AND WEST-SOUTHWEST 
OVER MEXICO IN THE UPPER LEVELS.  ZONAL WEST WINDS OF 50 TO 60 
KT ARE FOUND IN THE UPPER LEVELS OVER THE GULF OF MEXICO ... 
WHICH TURN CYCLONICALLY OVER THE WESTERN NORTH ATLANTIC BETWEEN 
20N AND 30N IN RESPONSE TO THE SLOWLY MOVING DEEP LAYER LOW 
SOUTH OF NOVA SCOTIA.  AT THE SURFACE ... WINDS OVER THE GULF OF 
MEXICO ARE PRIMARILY OUT OF THE SOUTHEAST AND ARE STRONGEST ... 
UP TO 20 KT ... IN THE SOUTHWESTERN GULF.  IN THE ATLANTIC A 
FRONTAL BOUNDARY THAT IS BECOMING STATIONARY EXTENDS FROM 22N72W 
TO 24N60W.  SOUTH OF THE FRONT WINDS ARE WEAK AND DISORGANIZED 
WHILE NORTH OF THE FRONT THE WINDS ARE WEAKLY FROM THE NORTH.  
SOME SHOWER ACTIVITY MAY BE ASSOCIATED ALONG THE FRONT.  A WEAK 
NEW DISTURBANCE/CLOSED LOW HAS FORMED AT THE SURFACE NEAR 30N77W 
... WHICH MAY HAVE DEVELOPED OFF OF THE WESTERN REMNANTS OF THE 
FRONT ALREADY MENTIONED.  NUMEROUS STRONG SHOWERS AND SOME 
THUNDERSTORMS ARE WITHIN A 75 NM RADIUS OF 28N76W ... SOMEWHAT 
SOUTH AND EAST OF THE WEAK CIRCULATION CENTER.

THE CARIBBEAN SEA...
ZONAL WESTERLY WINDS IN THE UPPER LEVELS PREVAIL OVER THE 
CARIBBEAN ... WHICH VARY IN STRENGTH FROM NEAR 30 KT NEAR SOUTH 
AMERICA TO 80 KT OVER THE GREATER ANTILLES.  THE EASTERLY 
SURFACE TRADEWINDS ARE MODERATE IN STRENGTH WITH WINDS UP TO 20 
KT.  THE ONLY SIGNIFICANT SHOWER ACTIVITY IN THE REGION WAS 
ALONG A BAND ALONG A LINE FROM 17N74W TO 15N79W ... ELSEWHERE IT 
IS SEASONALLY DRY.

THE REST OF THE ATLANTIC OCEAN...
UPPER LEVEL FLOW IS WESTERLY GENERALLY ABOUT 50 KT IN STRENGTH 
NORTH OF THE SUBTROPICAL RIDGE ... WHICH IS FOUND ALONG A LINE 
FROM 10N14W TO 5N30W TO 2N50W. EQUATORWARD OF THE UPPER RIDGE 
WEAK EASTERLIES PREVAIL.  AT THE SURFACE EASTERLY AND 
NORTHEASTERLY WINDS ARE FOUND SOUTH OF 32N ... DRIVEN BY A 
STRONG SURFACE HIGH PRESSURE NEAR 33N31W.  SOME SHOWERS MAY BE 
FOUND ALONG THE EARLIER MENTIONED FRONTAL BOUNDARY EAST OF 60W 
THAT IS ALONG 24N60W TO 25N56W TO 32N51W.  MORE WIDESPREAD AND 
MORE INTENSE SHOWER AND THUNDERSTORM ACTIVITY IS OCCURRING IN A 
BAND AHEAD OF THE FRONT IN SOUTHERLY WINDS.  THESE SHOWERS AND 
THUNDERSTORMS CAN BE FOUND WITHIN 60 NM OF A LINE GOING FROM 
22N54W TO 26N50W TO 32N46W.  ELSEWHERE NO SIGNIFICANT SHOWER 
ACTIVITY IS SEEN.

$$
CWL