Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 040603
TWDAT 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
105 AM EST WED MAR 04 2015

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
0545 UTC.

...SPECIAL FEATURES...

...GALE WARNING FOR THE SW CARIBBEAN... 

A GALE WARNING IS IN EFFECT FOR COLOMBIA COASTAL WATERS FROM 
FROM 11N TO 13N BETWEEN 74W AND 76W WITH ASSOCIATED SEAS RANGING 
BETWEEN 9 TO 12 FT. THESE CONDITIONS ARE FORECAST THROUGH 
WEDNESDAY AFTERNOON...RESUMING AGAIN DURING THE NIGHT HOURS. 
PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS 
MIAHSFAT2/ FZNT02 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...                                      

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL 
ATLANTIC NEAR 11N15W SW TO 03N19W WHERE THE ITCZ BEGINS AND 
CONTINUES ALONG 01S32W TO THE COAST OF NORTHERN BRAZIL NEAR 
02S44W. ISOLATED SHOWERS ARE WITHIN 100 NM EITHER SIDE OF THE 
ITCZ W OF 21W. 

...DISCUSSION...

GULF OF MEXICO...      

WATER VAPOR IMAGERY INDICATES RELATIVELY STRONG SUBSIDENCE IN 
ASSOCIATION WITH A BROAD MIDDLE TO UPPER LEVEL RIDGE CENTERED 
NEAR 90W. AT THE SURFACE...A 1028 MB HIGH PRESSURE CENTER OVER 
THE W ATLC NEAR 35N66W EXTENDS A RIDGE AXIS SW ACROSS THE 
FLORIDA PENINSULA AND THE GULF...THUS PROVIDING WITH SE WIND 
FLOW OF 10 TO 15 KT. WITH OVERALL STABLE CONDITIONS ALOFT AND AT 
THE SURFACE...FAIR WEATHER AND CLEAR SKIES DOMINATE S OF 26N. 
HOWEVER...LINGERING SHALLOW MOISTURE SUPPORTS ADVECTION FOG OVER 
THE NW GULF N OF 26N W OF 90W AND OVER THE NE GULF N OF 29N E OF 
87W...THIS COINCIDING WITH MEDIUM TO HIGH GOES-13 IFR 
PROBABILITIES OF FOG. BY EARLY THURSDAY MORNING...THE NEXT COLD 
FRONT IS EXPECTED TO EMERGE OFF THE TEXAS AND LOUISIANA COASTS 
INTRODUCING STRONG TO NEAR GALE FORCE NORTHERLIES...WITH GALE 
FORCE CONDITIONS POSSIBLE...ACROSS THE WESTERN AND NORTH-CENTRAL 
GULF WATERS THROUGH LATE THURSDAY.

CARIBBEAN SEA...    

BROAD UPPER LEVEL TROUGHING IS OBSERVED ON WATER VAPOR IMAGERY 
WITH AXIS EXTENDING FROM THE CENTRAL ATLC...THROUGH THE NORTHERN 
LEEWARD ISLANDS TO A BROAD BASE OVER PANAMA. RELATIVELY DRY AND 
STABLE AIR IS EMBEDDED WITHIN THIS TROUGHING ALOFT WHICH 
CONTINUE TO PROVIDE OVERALL FAIR CONDITIONS ACROSS THE BASIN. AT 
THE LOWER LEVELS...MOISTURE PATCHES CONTINUE TO MOVE ACROSS THE 
BASIN THUS ENHANCING SCATTERED SHOWERS OVER THE SE 
CARIBBEAN...PUERTO RICO...HISPANIOLA AND CENTRAL AMERICA COASTAL 
WATERS. TRADES OF 15 TO 20 KT DOMINATE OVER THE BASIN...EXCEPT 
FOR THE SW CARIBBEAN WHERE WINDS RANGE FROM 25 TO 30 
KT...INCREASING TO GALE FORCE WINDS ALONG THE COAST OF COLOMBIA. 
PLEASE SEE THE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. 
AS HIGH PRESSURE CURRENTLY ANCHORED ACROSS THE MID-ATLC U.S. 
COAST MOVES E-SE INTO THE SW NORTH ATLC WATERS...THE PRESSURE 
GRADIENT WILL STRENGTHEN ACROSS THE BASIN OVERNIGHT INTO 
WEDNESDAY AND PERSIST THROUGH THE REMAINDER OF THE WEEK. WINDS 
TO GALE FORCE IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA ARE 
EXPECTED TO PULSE DURING THE LATE NIGHT AND EARLY MORNING HOURS 
DURING THE NEXT SEVERAL DAYS.

...HISPANIOLA...                                                 

SHALLOW MOISTURE IN THE TRADEWIND FLOW IS SUPPORTING SCATTERED 
CLOUDS WITH POSSIBLE SHOWERS TONIGHT. MOIST AIR WILL CONTINUE TO 
FLOW OVER THE ISLAND THROUGH WED MORNING. DEEP LAYER DRY AIR IS 
FORECAST TO PREDOMINATE OVER THE ISLAND THROUGH SATURDAY 
MORNING THUS FAVORING FAIR WEATHER CONDITIONS.

ATLANTIC OCEAN...    

A MIDDLE TO UPPER LEVEL TROUGH OVER THE CENTRAL ATLC EXTENDING 
SW TO A BASE OVER THE SW CARIBBEAN SUPPORTS A COLD FRONT FROM 
30N52W SW TO 26N72W. SCATTERED SHOWERS ARE OCCURRING AHEAD OF 
THE FRONT N OF 27N W OF 30W. THE FRONT WILL CONTINUE TO 
GRADUALLY WEAKEN THROUGH WEDNESDAY AS HIGH PRESSURE MOVES OFF 
THE MID-ATLC COAST AND SETTLES INTO THE SW NORTH ATLC WATERS. 
OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS 
UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1038 MB 
HIGH CENTERED NE OF THE AZORES NEAR 45N17W. THE NEXT COLD FRONT 
ENTERS THE SW N ATLC WATERS FRIDAY MORNING.  

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

$$
RAMOS