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Atlantic Tropical Weather Discussion (Text)

000
AXNT20 KNHC 281746
TWDAT 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
105 PM EST SAT FEB 28 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...SPECIAL FEATURES...

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

A GALE WARNING IS IN EFFECT FOR COLOMBIA COASTAL WATERS FROM 
10.5N TO 13N BETWEEN 73W AND 77W AND IS FORECAST TO CONTINUE 
THROUGH THE AFTERNOON HOURS. GALE WINDS ARE EXPECTED TO RESUME 
SATURDAY NIGHT AND CONTINUE THROUGH EARLY MONDAY MORNING. 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 05N09W AND SW TO 01S22W WHERE THE ITCZ BEGINS AND 
CONTINUES ALONG 03S30W TO THE NORTHERN COAST OF BRAZIL NEAR 
03S39W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE 
WITHIN 200 NM N OF THE MONSOON TROUGH AND ITCZ AXIS.

...DISCUSSION...

GULF OF MEXICO...           

A BROAD SURFACE RIDGE ANCHORED BY A STRONG 1045 MB HIGH CENTERED 
OVER PENNSYLVANIA IS PROVIDING NE TO E SURFACE WINDS OF 15 TO 25 
KT ACROSS MOST OF THE BASIN. A SURFACE TROUGH EXTENDS FROM THE 
TX COAST NEAR 27N94W TO THE BAY OF CAMPECHE NEAR 19N94W. WINDS 
TO THE W OF THE TROUGH ARE FROM THE W TO NW AT 10 TO 15 KT WITH 
THE AFOREMENTIONED EASTERLIES TO THE E OF THE TROUGH. SCATTERED 
SHOWERS ARE WITHIN 50 NM OF THE TROUGH AXIS. A STATIONARY FRONT 
EXTENDS FROM THE WESTERN ATLC TO S FL NEAR FT LAUDERDALE TO THE 
GULF NEAR 25N82 TO 22N91W. THE COMBINATION OF UPPER LEVEL 
DIFFLUENCE FROM THE EXIT REGION OF THE SUBTROPICAL JET STREAM 
AND CONVERGENCE NEAR THE STATIONARY FRONT IS SUPPORTING SCATTERED 
TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS N OF THE 
STATIONARY FRONT TO THE NORTHERN GULF COAST E OF 91W...WITH THE 
GREATEST COVERAGE FROM 27N TO 30N BETWEEN CENTRAL FL AND 88W. 
THE STATIONARY FRONT WILL DISSIPATE THROUGH THIS AFTERNOON 
ACROSS THE SE GULF WHILE THE SURFACE TROUGH REMAINS NEARLY 
STATIONARY ACROSS THE SW GULF THROUGH SUNDAY. UPPER LEVEL 
SUPPORT FOR CONVECTION ACROSS THE EASTERN GULF WILL DIMINISH 
TONIGHT. THEREFORE...EXPECT AN OVERALL DECREASE IN SHOWER 
ACTIVITY ACROSS THE EASTERN BASIN THROUGH TONIGHT. SHOWERS WILL 
REMAIN POSSIBLE ACROSS THE WESTERN GULF NEAR THE SURFACE TROUGH 
THROUGH SUNDAY. 

CARIBBEAN SEA...    

AN UPPER LEVEL RIDGE CENTERED JUST E OF CENTRAL AMERICA PROVIDES 
NORTHERLY FLOW ALOFT WITH STRONG SUBSIDENCE AND DRY AIR IN THE 
MID TO UPPER LEVELS OVER MUCH OF THE BASIN. AN INVERTED UPPER 
TROUGH IS OVER THE E CARIBBEAN. AT THE SURFACE...A TIGHT 
PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE EASTERN US AND 
LOWER PRESSURE OVER S AMERICA IS PRODUCING GALE FORCE WINDS OFF 
THE COAST OF COLOMBIA. SEE THE SPECIAL FEATURES SECTION FOR MORE 
DETAILS. E TO NE TRADE WINDS OF 15 TO 25 KT PREVAIL ACROSS THE 
REMAINDER OF THE CARIBBEAN. LOW LEVEL MOISTURE IN THE TRADE WIND 
FLOW IS SUPPORTING PATCHES OF SHOWERS N OF A LINE FROM 15N84W TO 
11N62W. THIS INCLUDES THE GULF OF HONDURAS...JAMAICA...PORTIONS 
OF HISPANIOLA...PUERTO RICO...AND THE LESSER ANTILLES. LITTLE 
CHANGE IS EXPECTED ACROSS THE BASIN OVER THE NEXT 48 HOURS. 

...HISPANIOLA...                                                 

A SHALLOW MOIST AIRMASS CONTINUES TO MOVE ACROSS THE 
ISLAND...SUPPORTING CLOUDINESS AND SCATTERED SHOWERS...MAINLY 
ACROSS THE DOMINICAN REPUBLIC. THESE CONDITIONS ARE EXPECTED TO 
CONTINUE THROUGH SUNDAY.

ATLANTIC OCEAN...    

A 1023 MB LOW N OF THE AREA OF DISCUSSION SUPPORTS A FRONT THAT 
EXTENDS SW AND INTO OUR AREA AS A STATIONARY FRONT NEAR 32N64W 
TO 28N75W TO THE FL COAST NEAR 26N80W. UPPER LEVEL DIFFLUENCE 
ALONG THE EXIT REGION OF THE SUBTROPICAL JET IS COMBINING WITH 
LOW LEVEL MOISTURE AND CONVERGENCE IN THE VICINITY OF THE 
STATIONARY FRONT TO PRODUCE A LARGE AREA OF CLOUDINESS WITH 
SHOWERS AND ISOLATED THUNDERSTORMS THAT EXTENDS FROM THE E 
GULF...ACROSS CENTRAL FL AND INTO THE ATLC WITHIN 175 NM NW OF 
THE STATIONARY FRONT. ISOLATED SHOWERS AND THUNDERSTORMS ARE 
ALSO WITHIN 50 NM S OF THE STATIONARY FRONT. A LARGE RIDGE 
ANCHORED BY A 1039 MB HIGH CENTERED S OF THE AZORES SUPPORTS 
GENERALLY FAIR WEATHER ACROSS THE CENTRAL AND EASTERN ATLC S OF 
32N. A TIGHT PRESSURE GRADIENT BETWEEN THE AZORES HIGH AND LOWER 
PRESSURE OVER THE SUBTROPICAL E ATLC IS PRODUCING STRONG TO NEAR 
GALE FORCE WINDS OFF THE COAST OF N MOROCCO. OVER THE NEXT 24 
HOURS THE STATIONARY FRONT WILL GRADUALLY DISSIPATE...WITH 
SHOWERS AND THUNDERSTORMS REMAINING POSSIBLE THROUGH SUNDAY 
MORNING OFF THE COAST OF N AND CENTRAL FL INCLUDING THE NORTHERN 
BAHAMAS. 

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

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LATTO