000
AXNT20 KNHC 091045
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU MAY 09 2013

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1045 UTC.

...ITCZ/MONSOON TROUGH...                                     

THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU NEAR 
11N15W TO 7N17W TO 4N20W. THE INTERTROPICAL CONVERGENCE ZONE 
AXIS EXTENDS FROM 4N20W TO 0N33W TO THE COAST OF BRAZIL AT 
3S40W. WIDELY SCATTERED MODERATE CONVECTION IS S OF THE MONSOON 
TROUGH FROM 1N-7N BETWEEN 1W-16W. SCATTERED MODERATE CONVECTION 
IS ALONG THE ITCZ FROM 3N-6N BETWEEN 20W-25W. WIDELY SCATTERED 
MODERATE CONVECTION IS FROM 6N-0N BETWEEN 30W-50W.

...DISCUSSION...

GULF OF MEXICO...                                               

AS OF 0900 UTC... A 1020 MB HIGH IS CENTERED NEAR TAMPA FLORIDA 
PRODUCING MOSTLY FAIR WEATHER. 10-15 KT SURFACE WINDS ARE NOTED 
OVER MOST OF THE GULF. IN THE UPPER LEVELS...AN UPPER LEVEL 
TROUGH IS OVER THE GULF WITH AXIS ALONG 85W. AN AREA OF UPPER 
LEVEL MOISTURE AND SCATTERED HIGH CLOUDS ARE OVER TEXAS AND THE 
NW GULF. STRONG SUBSIDENCE IS OVER FLORIDA...AS WELL AS OVER THE 
BAY OF CAMPECHE AND THE YUCATAN PENINSULA. EXPECT OVER THE NEXT 
24 HOURS FOR THE SURFACE HIGH TO DISSIPATE. ALSO EXPECT  
SCATTERED SHOWERS TO BE OVER E TEXAS...AND OVER W CUBA AND THE 
STRAITS OF FLORIDA. 
 
CARIBBEAN SEA...                                                

AS OF 0900 UTC...A SURFACE TROUGH EXTENDS FROM S OF JAMAICA AT 
17N80W TO N COLOMBIA AT 9N77W MOVING W. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS OVER THE SW CARIBBEAN FROM 8N-11N 
BETWEEN 75W-80W. SCATTERED SHOWERS ARE WITHIN 120 NM OF THE 
REMAINDER OF THE TROUGH. ANOTHER SURFACE TROUGH EXTENDS FROM THE 
SOUTHERN BAHAMAS AT 24N72W TO HAITI AT 18N74W MOVING WNW. 
ISOLATED MODERATE CONVECTION IS FROM 18N-24N BETWEEN 65W-75W TO 
INCLUDE HISPANIOLA AND THE SOUTHERN BAHAMAS. LOCALIZED FLOODING 
IS POSSIBLE OVER HISPANIOLA. FURTHER E...THE TAIL END OF A 
SHEARLINE IS OVER THE LEEWARD ISLANDS FROM 18N60W TO 20N67W. 
SCATTERED SHOWERS ARE WITHIN 60 NM OF THE SHEARLINE. IN THE 
UPPER LEVELS... THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE W 
CARIBBEAN W OF 75W. THE WESTERN PORTION OF AN UPPER LEVEL HIGH 
IS OVER THE REMAINDER OF THE CARIBBEAN PRODUCING SW UPPER LEVEL 
FLOW. UPPER LEVEL SUBSIDENCE IS OVER THE W CARIBBEAN AND CENTRAL 
AMERICA W OF 75W. SIGNIFICANT UPPER LEVEL MOISTURE AND BROKEN 
HIGH CLOUD OVER THE E CARIBBEAN. EXPECT OVER THE NEXT 24 HOURS 
FOR SHOWERS AND THUNDERSTORMS TO EXTEND FROM HAITI TO PANAMA DUE 
TO THE SURFACE TROUGHS...AND FOR CONTINUED SHOWERS TO BE OVER 
THE LEEWARD ISLANDS DUE TO THE SHEARLINE. 

ATLANTIC OCEAN...                                           

A SURFACE TROUGH IS OVER THE SOUTHERN BAHAMAS WITH SCATTERED 
SHOWERS. A 1030 MB HIGH IS OVER THE W ATLANTIC NEAR 36N55W 
PRODUCING FAIR WEATHER. A SURFACE TROUGH IS OVER THE E ATLANTIC 
FROM 30N30W TO 26N37W. ANOTHER SURFACE TROUGH IS W OF THE CANARY 
ISLANDS FROM 30N20W TO 23N27W. SCATTERED SHOWERS ARE WITHIN 30 
NM OF THE TROUGH. A SHEARLINE IS OVER THE TROPICAL ATLANTIC FROM 
23N27W TO 18N40W TO 15N50W TO THE LEEWARD ISLANDS NEAR 18N60W. 
SCATTERED SHOWERS ARE WITHIN 90 NM OF THE SHEARLINE. IN THE 
UPPER LEVELS... AN UPPER LEVEL TROUGH IS OVER THE E ATLANTIC N 
OF 20N BETWEEN 20W-50W SUPPORTING THE SURFACE TROUGHS. EXPECT 
OVER THE NEXT 24 HOURS FOR THE TROUGH OVER THE SOUTHERN BAHAMAS 
TO CONTINUE TO PRODUCE SHOWERS AND THUNDERSTORMS. ALSO EXPECT 
THE PORTION OF THE SHEARLINE E OF THE LEEWARD ISLANDS TO REMAIN 
ACTIVE WITH SHOWERS.  
 
FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

AT THE REQUEST OF METEO-FRANCE AND THE METEOROLOGICAL SERVICES OF 
HAITI AND THE DOMINICAN REPUBLIC...THE TROPICAL ANALYSIS AND 
FORECAST BRANCH (TAFB) WILL BEGIN PROVIDING...ON A TEMPORARY 
BASIS...A SEPARATE DETAILED SECTION WITHIN THE ATLANTIC TROPICAL 
WEATHER DISCUSSION (TWDAT). IT WILL COVER BOTH HAITI AND THE 
DOMINICAN REPUBLIC DUE TO THE SHARED GEOGRAPHY OF BOTH COUNTRIES 
ON THE ISLAND OF HISPANIOLA.

THE SECTION BEGINS ON MAY 15 2013 AT 1800 UTC...2 PM EDT. IT 
WILL PROVIDE GUIDANCE FOR SIGNIFICANT WEATHER EVENTS THAT ARE 
EXPECTED TO IMPACT THE REGION THROUGH 48 HOURS...WITH THE FOCUS 
ON ASSESSING THE POTENTIAL FOR HEAVY RAINFALL.

$$
FORMOSA