000
AXNT20 KNHC 131804
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
105 PM EST WED NOV 13 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...                                          
A GALE WARNING IS CURRENTLY IN EFFECT AS A COLD FRONT IS 
ANALYZED FROM THE SOUTHERN FLORIDA PENINSULA W-SW TO THE EAST-
SOUTHERN MEXICO COAST NEAR 20N97W. THE FRONT IS FORECAST TO 
CONTINUE PUSHING ACROSS THE REMAINDER OF THE GULF OF MEXICO AND 
PORTIONS OF THE SW NORTH ATLC WITH GALE FORCE NE WINDS WEST OF 
THE FRONTAL BOUNDARY. SEE LATEST HIGH SEAS FORECAST UNDER 
AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...                                     
THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR 
07N13W TO 09N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS 
EXTENDS FROM 09N22W TO 07N32W TO 09N41W. A SURFACE TROUGH IS 
ANALYZED WEST OF THE ITCZ AXIS FROM 14N46W TO 09N46W. EVEN 
THOUGH SSMI TOTAL PRECIPITABLE WATER IMAGERY SHOW THE TROUGH IS 
EMBEDDED WITHIN A HIGH MOIST ENVIRONMENT NEAR THE 
SURFACE...STRONG W-NW WIND SHEAR AND DRY AIR SUBSIDENCE FROM THE 
MIDDLE-LEVELS IS HINDERING CONVECTION AT THE TIME.

...DISCUSSION...

GULF OF MEXICO...                                               
A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM NE MAINE 
SW TO BASE OVER THE SE GULF NEAR 25N84W SUPPORTS A COLD FRONT 
ANALYZED FROM THE SOUTHERN FLORIDA PENINSULA NEAR 25N81W W-SW TO 
24N90W TO THE EAST-SOUTHERN MEXICO COAST NEAR 20N97W. MIDDLE TO 
UPPER LEVEL SOUTHWESTERLY FLOW AHEAD OF AND SOUTH OF THE UPPER 
LEVEL TROUGH CONTINUES TO ADVECT MOISTURE ACROSS THE BASIN...THE 
FLORIDA PENINSULA AND INTO THE SW NORTH ATLC REGION. OVERCAST 
SKIES ARE NOTED ON SATELLITE IMAGERY BASIN-WIDE WITH ISOLATED 
SHOWERS WEST OF THE COLD FRONT. LOW-LEVEL MOISTURE CONVERGENCE 
AND MIDDLE-LEVEL DIFFLUENCE OVER THE SW GULF IS SUPPORTING 
SCATTERED SHOWERS S OF 20W E OF 94W. SCATTERED MODERATE 
CONVECTION AND ISOLATED TSTMS ARE NOTED IN THE YUCATAN CHANNEL. 
THE MAIN IMPACT FROM THE FRONT IS GALE FORCE NORTH-NORTHEASTERLY 
WINDS IN WAKE OF THE FRONT DUE TO A STRONG PRESSURE GRADIENT AND 
STRONG SURFACE RIDGING BUILDING OVER THE BASIN AND EXPECTED TO 
CONTINUE THROUGH EARLY THURSDAY. THE PRESSURE GRADIENT AND 
ASSOCIATED WIND FIELD IS EXPECTED TO RELAX THROUGH LATE 
THURSDAY. SEE THE SPECIAL FEATURE SECTION ABOVE.

CARIBBEAN SEA...                                                
A MIDDLE TO UPPER LEVEL ANTICYCLONE CENTERED NE OF PUERTO RICO 
EXTENDS A RIDGE AXIS S-SW TO THE CENTRAL AND EASTERN CARIBBEAN 
AND INFLUENCES THIS REGION WITH DRY AIR SUBSIDENCE...THUS 
SUPPORTING FAIR WEATHER. IN THE FAR NW CARIBBEAN...LOW-LEVEL 
MOISTURE CONVERGENCE SUPPORTS SCATTERED SHOWERS AND TSTMS S OF 
22N W OF 84W WHILE MIDDLE-LEVEL DIFFLUENCE ENHANCES SIMILAR 
CONVECTION BETWEEN JAMAICA AND EASTERN HONDURAS FROM 15N-19N. IN 
THE SW CARIBBEAN...A 1008 MB LOW PRESSURE CENTER IS SUPPORTING A 
CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION AND TSTMS S OF 
13N W OF 75W. WITHIN THE NEXT 24 HOURS...THE LOW PRESSURE IS 
EXPECTED TO STALL WHILE A COLD FRONT ENTERS THE FAR NW BASIN.

...HISPANIOLA...                                                 
A MIDDLE TO UPPER LEVEL ANTICYCLONE CENTERED NE OF PUERTO RICO 
EXTENDS A RIDGE AXIS SW ACROSS THE ISLAND AND INFLUENCES WITH 
DRY AIR SUBSIDENCE...THUS SUPPORTING FAIR WEATHER. THE RIDGE IS 
EXPECTED TO REMAIN IN THE VICINITY OF THE ISLAND THROUGH FRIDAY 
AFTERNOON WHILE A DRY AIRMASS ENTERS THE ISLAND FROM THE EAST 
WHICH WILL INHIBITS DEVELOPMENT OF DEEP CONVECTION. 
 
ATLANTIC OCEAN...                                                
A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM NE MAINE 
SW TO BASE OVER THE SE GULF NEAR 25N84W SUPPORTS A COLD FRONT 
ANALYZED FROM 30N71W SW TO THE SOUTHERN FLORIDA PENINSULA NEAR 
26N80W. A PRE-FRONTAL TROUGH IS NOTED SE OF THE FRONT FROM 
29N65W TO 23N76W. MIDDLE TO UPPER LEVEL SOUTHWESTERLIES CONTINUE 
TO ADVECT MOISTURE FROM OVER THE GULF OF MEXICO TO OVER PORTIONS 
OF THE SW NORTH ATLC AHEAD OF THE COLD FRONT TO SUPPORT 
SCATTERED SHOWERS AND TSTMS N OF 28N BETWEEN 63W-66W. THE 
REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE 
OF SURFACE RIDGING ANCHORED BY A 1038 MB HIGH CENTERED WELL 
NORTH OF THE DISCUSSION AREA NEAR 44N16W.

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

$$
NR