000
AXNT20 KNHC 120556
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
205 AM EDT SUN JUN 12 2011

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...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 35W S OF 09N MOVING W AT 10 KT.  THIS 
WAVE IS SUBTLE AND NOT WELL DEFINED IN THE OBSERVATIONS OR IN 
THE TOTAL PRECIPITABLE WATER IMAGERY.  THE WAVE IS...HOWEVER... 
CAN BE IDENTIFIED IN THE GFS AND ECMWF MODEL ANALYSES AND IT IS 
ALSO ASSOCIATED WITH ENHANCED CONVECTION ALONG THE ITCZ. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM OF THE WAVE AXIS 
BETWEEN 3N AND 7N.

TROPICAL WAVE EXTENDS FROM 16N46W TO 4N49W MOVING WNW 10-12 KT.  
THE SYSTEM SHOWS A CLASSIC INVERTED-V STRUCTURE IN THE VISIBLE 
AND SHORT-WAVE INFRARED IMAGERY.  THE TOTAL PRECIPITABLE WATER 
IMAGERY ALSO INDICATES A WELL-DEFINED MAXIMUM OF MOISTURE ON THE 
EASTERN FLANK OF THE WAVE AXIS.  NO SIGNIFICANT DEEP CONVECTION 
IS ASSOCIATED WITH THIS TROPICAL WAVE AT THIS TIME.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM INLAND WEST AFRICA AT 16N00W TO 
14N10W TO THE COAST AT 14N16W TO 6N21W. THE ITCZ THEN CONTINUES 
FROM THERE ALONG 5N32W TO SOUTH AMERICA AT 8N59W.  A SEPARATE 
MONSOON TROUGH EXTENDS FROM THE EAST COAST OF COSTA RICA AT 
10N83W EASTWARD INTO THE SW CARIBBEAN AND INTO COLUMBIA AT 
11N75W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OVER 
INLAND WEST AFRICA WITHIN 240 NM S OF THE MONSOON TROUGH AXIS 
BETWEEN 00W TO 07W.  SIMILAR CONVECTION IS ALONG THE COAST OF 
WEST AFRICA FROM 4N-8N BETWEEN 10W-16W.  SCATTERED MODERATE 
CONVECTION IS WITHIN 120 NM OF THE ITCZ AXIS BETWEEN 32W AND 
40W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 
120 NM OF THE MONSOON TROUGH AXIS FROM COSTA RICA TO 80W.

...DISCUSSION...

GULF OF MEXICO...
A 1014 MB HIGH IS CENTERED OVER THE N GULF OF MEXICO AT 
29N87W...WHICH IS HELPING TO PRODUCE GENERALLY FAIR WEATHER WITH 
LIGHT WINDS AND VERY LITTLE CLOUDINESS.  THE ONLY SIGNIFICANT 
RAINFALL IS SOME SHOWERS AND THUNDERSTORMS JUST OFF OF THE COAST 
OF MISSISSIPPI AND ALABAMA AND IN THE STRAITS OF FLORIDA.  IN 
THE UPPER LEVELS...NE TO SW ORIENTED TROUGHING IS SEEN ACROSS 
THE GULF OF MEXICO AND STRONG SUBSIDENCE COVERS THE AREA.  
LITTLE CHANGE IN THE THESE CONDITIONS ARE ANTICIPATED DURING THE 
NEXT DAY.

CARIBBEAN SEA...
A SURFACE TROUGH EXTENDS SOUTHWESTWARD FROM THE YUCATAN CHANNEL 
TO THE YUCATAN PENINSULA FROM 22N86W TO 15N92W.  SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS OCCURRING WITHIN 240 NM 
EAST OF THE AXIS PRIMARILY OVER GUATEMALA AND HONDURAS.  AS 
MENTIONED ABOVE...A MONSOON TROUGH EXTENDS INTO THE SW CARIBBEAN 
AND IS ASSOCIATED WITH CONVECTION OVER COSTA RICA AND PANAMA.  
SHOWERS ARE ALSO OCCURRING OVER WESTERN CUBA AS SEEN FROM THE 
CASABLANCA RADAR IN ASSOCIATION WITH A SURFACE TROUGH JUST NORTH 
OF THE ISLAND.  A MODERATE SURFACE PRESSURE GRADIENT IS 
PRODUCING EASTERLY WINDS ACROSS THE CARIBBEAN OF GENERALLY 10 TO 
20 KT...THOUGH NORTH OF NE COLUMBIA THE TRADEWINDS REACH UP TO 
25 KT.  IN THE UPPER LEVELS...AN UPPER HIGH IS CENTERED OVER 
HISPANIOLA AND IS PROMOTING GENERALLY FAIR WEATHER ACROSS MOST 
OF THE CARIBBEAN.  A SUBTROPICAL JET OF SW WINDS TO 50 KT OCCURS 
OVER THE NW CARIBBEAN AND IS A RESULT OF THE UPPER HIGH AND THE 
UPPER TROUGH OVER THE GULF OF MEXICO.  LITTLE CHANGE IN THE 
WINDS ARE EXPECTED DURING THE NEXT DAY...WITH LIKELY LESS RAIN 
OVER CUBA BUT CONTINUED RAINFALL OVER CENTRAL AMERICA.    
 
ATLANTIC OCEAN...
A 1010 MB LOW IS CENTERED N OF THE BAHAMAS AT 28N77W. A SURFACE 
TROUGH EXTENDS FROM 31N74W TO THE LOW CENTER TO THE STRAITS OF 
FLORIDA AT 23N81W.  DEEP CONVECTION HAS CEASED OVER THE BAHAMAS 
THIS EVENING...BUT SHOWERS LIKELY HAVE BEEN CONTINUING FOR THE 
NORTHERN AND CENTRAL BAHAMAS.  SCATTERED MODERATE CONVECTION IS 
OCCURRING FROM 24N-28N BETWEEN 66W-71W. A DISSIPATING COLD FRONT 
IS OVER THE CENTRAL ATLANTIC FROM 32N38W TO 24N50W. ISOLATED 
MODERATE CONVECTION IS FROM 20N-24N BETWEEN 48W-56W IN 
ASSOCIATION WITH A WEAK 1016 MB SURFACE LOW AT 23N57W WITH A 
TRAILING TROUGH TO ITS SOUTHWEST TO 15N61W. A 1024 MB HIGH IS 
OVER THE E ATLANTIC NEAR 32N25W PRODUCING FAIR WEATHER.  ALL OF 
THE ATLANTIC OCEAN IN OUR AREA OF RESPONSIBILITY HAS WINDS 20 KT 
OR LESS.  MOST OF THE REGION WILL SEE LITTLE CHANGE IN THE NEXT 
DAY...THOUGH THE BAHAMAS WILL LIKELY HAVE LESS RAIN AS THE LOW N 
OF THE BAHAMAS PULLS NORTHWARD AND WEAKENS.

F0R ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
LANDSEA