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Atlantic Tropical Weather Discussion (Text)

000
AXNT20 KNHC 272015
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
105 PM EST TUE JAN 27 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 IN W ATLC...

A GALE WARNING IS IN EFFECT N OF 28N BETWEEN 68W AND 78W ALONG A 
FAST MOVING COLD FRONT THAT EXTENDS FROM 31N64W TO 21N76W. THIS 
GALE WARNING WILL CONTINUE THROUGH THIS EVENING AS THE FRONT 
MOVES E WHERE IT WILL MERGE WITH ANOTHER FRONTAL BOUNDARY 
CURRENTLY LOCATED E OF THE PREVIOUS FRONT. SEE THE HIGH SEAS 
FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE 
DETAILS.

...ITCZ/MONSOON TROUGH...                                     

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLANTIC NEAR 6N10W TO 2N21W WHERE THE ITCZ BEGINS AND CONTINUES 
TO 2N40W TO SOUTH AMERICA NEAR 1N50W. WIDELY SCATTERED MODERATE 
CONVECTION IS FROM 1N-6N BETWEEN 3W-14W...FROM 3N-5N BETWEEN 17W-
22W...AND FROM 1N-5N BETWEEN 28W-44W. 


...DISCUSSION...

GULF OF MEXICO...

A 1023 MB SURFACE HIGH IS CENTERED OVER THE WESTERN GULF OF 
MEXICO NEAR 23N96W. 10-20 KT ANTICYCLONIC SURFACE WINDS ARE OVER 
THE GULF WITH STRONGEST WINDS OVER THE NE GULF. MOSTLY FAIR 
WEATHER IS OVER THE GULF WITH SCATTERED COLD AIR STRATOCUMULUS 
CLOUDS OVER THE SE GULF. COLD AIR ADVECTION FOLLOWING A COLD 
FRONT REMAINS OVER FLORIDA AND THE E GULF E OF 85W. IN THE UPPER 
LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE E GULF E 
OF 90W. AN UPPER LEVEL RIDGE IS OVER THE W GULF...TEXAS...AND 
MEXICO WITH AXIS ALONG 100W. STRONG SUBSIDENCE IS OVER THE 
ENTIRE GULF. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. 

CARIBBEAN SEA... 

A COLD FRONT EXTENDS FROM E CUBA AT 21N76W TO 17N80W TO THE N 
COAST OF HONDURAS AT 16N87W. A PREFRONTAL SHEAR LINE EXTENDS 
FROM HAITI AT 20N73W TO COSTA RICA AT 11N83W. 15-20 KT NORTHERLY 
SURFACE WINDS ARE N OF THE SHEAR LINE. SCATTERED SHOWERS ARE 
OVER THE WINDWARD PASSAGE AND HAITI. MORE SHOWERS ARE OVER THE 
SW CARIBBEAN AND CENTRAL AMERICA FROM 9N-17N W OF 79W TO INCLUDE 
PORTIONS OF COSTA RICA...NICARAGUA...HONDURAS...AND GUATEMALA. 
ELSEWHERE...RADAR IMAGERY SHOWS MORE SCATTERED SHOWERS S OF 
PUERTO RICO AND THE MONA PASSAGE. IN THE UPPER LEVELS...THE TOP 
OF A BROAD RIDGE IS OVER THE CARIBBEAN WITH AXIS ALONG 70W. 
STRONG SUBSIDENCE IS OVER THE ENTIRE CARIBBEAN SEA AND CENTRAL 
AMERICA. EXPECT OVER THE NEXT 24 HOURS FOR THE FRONT TO BECOME 
QUASI-STATIONARY AND DISSIPATING.  

...HISPANIOLA... 

PRESENTLY SCATTERED SHOWERS ARE OVER HAITI AND THE WINDWARD 
PASSAGE DUE TO PREFRONTAL ACTIVITY. FURTHER E...TRADEWINDS ARE 
ADVECTING MORE SCATTERED SHOWERS OVER THE MONA PASSAGE AND THE 
EASTERN DOMINICAN REPUBLIC. EXPECT OVER THE NEXT 24 HOURS FOR 
MORE SHOWERS OVER ALL OF HISPANIOLA DUE TO THE COMBINATION OF 
BOTH SOURCES.  

ATLANTIC OCEAN... 

A GALE IS OVER THE W ATLANTIC. SEE ABOVE. A COLD FRONT IS OVER 
THE WESTERN ATLANTIC FROM 31N64W TO E CUBA AT 21N76W. A 
DISSIPATING COLD FRONT IS FURTHER E EXTENDING FROM 31N61W TO 
HAITI AT 20N72W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM 
E OF THE DISSIPATING COLD FRONT N OF 23N. SCATTERED SHOWERS ARE 
ELSEWHERE E OF THE COLD FRONT N OF 23N. A LARGE 1043 MB HIGH IS 
OVER THE E ATLANTIC NEAR THE AZORES AT 40N24W. SURFACE RIDGING 
IS N OF 20N E OF 50W. OF NOTE IN THE UPPER LEVELS...AN UPPER 
LEVEL TROUGH IS OVER THE W ATLANTIC W OF 60W SUPPORTING THE 
FRONTAL SYSTEMS. AN UPPER LEVEL LOW IS CENTERED FURTHER E AT 
27N30W. EXPECT OVER THE NEXT 24 HOURS FOR THE FRONTAL SYSTEMS TO 
MERGE WITH CONTINUED CONVECTION. 

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

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FORMOSA