000
AXNT20 KNHC 020706
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT MAY 02 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0330 UTC.

...THE ITCZ...

THE ITCZ AXIS EXTENDS FROM W AFRICA AT 06N10W TO 03N20W TO THE 
EQUATOR AT 30W TO NE BRAZIL NEAR 03S39W. WIDELY SCATTERED 
MODERATE CONVECTION IS FROM 03S TO 04N BETWEEN 11W AND 20W...AND 
FROM 02N TO 05N BETWEEN 20W AND 26W. SCATTERED MODERATE 
CONVECTION IS E OF 11W TO THE COAST OF AFRICA FROM 03N TO 06N.  

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH LIES ACROSS THE GULF OF MEXICO FROM THE NE GULF 
THROUGH THE WESTERN BAY OF CAMPECHE...WITH STRONG SUBSIDENCE ON 
THE EASTERN SIDE OF THE TROUGH AXIS OVER MUCH OF THE GULF N OF 
25N WHERE FAIR WEATHER PREVAILS.  MOSTLY MID TO HIGH LEVEL 
CLOUDINESS IS FOUND S OF 25N WHERE THE SUBTROPICAL UPPER JET ON 
THE EASTERN SIDE OF THE TROUGH IS TRANSPORTING MOISTURE EASTWARD 
OVER THE AREA.  THERE IS NO SIGNIFICANT CONVECTION OVER GULF 
WATERS.  OVER MEXICO...NUMEROUS MODERATE CONVECTION CAN BE FOUND 
NW OF MONTERREY AND S OF THE RIO GRANDE AND SCATTERED MODERATE 
CONVECTION CAN BE FOUND S OF MEXICO CITY.  AT THE 
SURFACE...SOUTHEASTERLY FLOW CAN BE FOUND OVER MOST OF THE AREA. 
THE STRONGEST WINDS...IN THE 15 TO 20 KT RANGE...ARE IN THE 
WESTERN GULF WHERE THE GRADIENT BETWEEN THE WESTERN EDGE OF THE 
ATLC RIDGE AXIS OVER THE EASTERN GULF OF MEXICO AND TROUGHING 
OVER TEXAS AND NORTHEASTERN MEXICO IS STRONGEST.  MEAN WINDS IN 
AND JUST S OF THE FL KEYS HAVE DIMINISHED BELOW 20 KT AS THE 
WESTERN EDGE OF THE ATLC RIDGE HAS WEAKENED SLIGHTLY OVER THE 
LAST FEW HOURS.  HOWEVER...THE 2336 UTC QUIKSCAT PASS STILL 
SHOWS A BROAD AREA OF WINDS TO 25 KT ALONG THE COAST OF CUBA 
WITHIN THE STRAITS OF FL.  LITTLE CHANGE IN THE PATTERN IS 
EXPECTED UNTIL LATE SUN WHEN A COLD FRONT IS EXPECTED TO PUSH 
SOUTH TO THE TEXAS COAST WHILE HIGH PRES IN THE CENTRAL ATLC 
MOVES SOUTHWARD...SHIFTING THE STRONGEST WINDS EASTWARD OVER THE 
CENTRAL AND EASTERN GULF.

CARIBBEAN SEA...
AN UPPER LEVEL RIDGE CURRENTLY LIES OVER MUCH OF THE CARIBBEAN 
ON THE SE SIDE OF THE TROUGH OVER THE GULF OF MEXICO.  THERE IS 
LITTLE DEEP CONVECTION OVER FORECAST WATERS WITH THE EXCEPTION 
OF SOME WIDELY SCATTERED SHOWERS IN THE GULF OF HONDURAS AND E 
OF NICARAGUA TO 80W.  INLAND...SCATTERED MODERATE CONVECTION CAN 
BE FOUND BETWEEN NW HONDURAS AND SOUTHERN MEXICO.  TO THE 
EAST...A DEEP LAYER TROUGH NE OF THE CARIBBEAN IS FOCUSING MOIST 
AIR OVER THE LEEWARD ISLANDS WHERE PRECIPITABLE WATER VALUES AND 
SHOWER ACTIVITY HAVE BEEN INCREASING OVER THE LAST 24 HOURS. DRY 
AIR ALOFT IS CURRENTLY WRAPPING S OF THE ASSOCIATED UPPER LEVEL 
LOW...PASSING OVER THE NE CARIBBEAN. THE QUIKSCAT PASS FROM 2338 
UTC SHOWS A BROAD AREA OF WINDS IN THE 20 TO 25 KT RANGE ACROSS 
THE CENTRAL CARIBBEAN...WITH THE HIGHEST WINDS ALONG THE COAST 
OF COLOMBIA AND IN THE WINDWARD PASSAGE.  ELSEWHERE...TRADE 
WINDS ARE GENERALLY 20 KT OR LESS.  TRADE WINDS ARE EXPECTED TO 
DIMINISH SLIGHTLY OVER THE NEXT DAY.
   
ATLANTIC OCEAN...
THE WEATHER OVER THE ATLC IS DOMINATED BY 1033 MB HIGH PRES NEAR 
40N49W.  STRONG SUBSIDENCE CAN BE FOUND BETWEEN 59W AND 75W. A 
DEEP LAYER TROUGH CAN BE FOUND IN THE VICINITY OF 57W FROM 15N 
TO 25N.  THIS TROUGH IS POOLING LOW TO MID LEVEL MOISTURE 
THROUGH THE LESSER ANTILLES NORTHWARD TO THE SURFACE TROUGH.  
SCATTERED MODERATE CONVECTION ASSOCIATED WITH THE TROUGH CAN BE 
FOUND FROM FROM 23N TO 26N BETWEEN 54W AND 57W WITH MORE 
ISOLATED CONVECTION FOUND E OF THIS AREA TO 48W.  THE QUIKSCAT 
PASSES FROM AROUND 2154 AND 2334 UTC SHOW THE HIGHEST WINDS 
ALONG NW SIDE OF THIS TROUGH INTO THE SOUTHERN BAHAMAS AND 
SOUTHERN STRAITS OF FL...MAINLY BETWEEN THE SURFACE TROUGH AND 
THE RIDGE AXIS.  TRADE WINDS OVER 20 KT ARE CURRENTLY CONFINED 
GENERALLY S OF 12N E OF 60W.  STRONG SUBSIDENCE S OF 12N E OF 
45W IS LIMITING CONVECTION ALONG THE ITCZ.  OVER THE NEXT 24 
HOURS...LOOK FOR THE DEEP LAYER TROUGH TO BREAKDOWN AS THE UPPER 
LEVEL SYSTEM SHIFTS E AND MERGES WITH THE TROUGH JUST N OF THE 
AREA ALONG 45W WHILE THE LOW LEVEL SYSTEM CONTINUES W WITH THE 
MEAN FLOW S OF THE RIDGE AXIS.

$$
SCHAUER CLARK