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000
AXNT20 KNHC 271008
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED MAY 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1000 UTC.


...TROPICAL WAVES...

A TROPICAL WAVE IS W OF THE ITCZ FROM THE EQUATOR TO 10N WITH AXIS NEAR 48W...MOVING W AT 5 TO 10 KT DURING THE LAST 24 HOURS. SSMI TPW IMAGERY SHOW THE WAVE IS EMBEDDED WITHIN ABUNDANT MOISTURE IN THE MIDDLE TO LOWER LEVELS. SATELLITE DERIVED WINDS AND MODEL GUIDANCE SHOW A DIFFLUENT ENVIRONMENT ALOFT THAT SUPPORT SCATTERED MODERATE CONVECTION WITHIN 160 NM AHEAD OF THE WAVE AXIS AND ISOLATED MODERATE CONVECTION E OF IT. FURTHER CONVECTION IS BEING HINDERED MAINLY BY STRONG DEEP LAYER WIND SHEAR.


...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL ATLANTIC NEAR 10N14W TO 06N20W. THE ITCZ BEGINS NEAR 06N20W AND CONTINUES ALONG 05N30W TO EAST OF A TROPICAL WAVE NEAR 04N45W. SCATTERED MODERATE CONVECTION AND TSTMS ARE FROM 04N TO 10N E OF 20W. FOR CONVECTION ASSOCIATED WITH THE TROPICAL WAVE SEE THE SECTION ABOVE.


...DISCUSSION...

GULF OF MEXICO...

SURFACE LOW PRESSURE OVER MEXICO EXTENDS E TO THE SW GULF WHILE HIGH PRESSURE OVER THE W ATLANTIC CONTINUES TO EXTEND A RIDGE AXIS SW ACROSS THE FLORIDA PENINSULA AND INTO THE NORTHERN AND EASTERN GULF. EASTERLY TO SOUTHEASTERLY WIND FLOW OF 15 TO 20 KT ASSOCIATED WITH THE RIDGE DOMINATES THE GULF AND ADVECTS LOW LEVEL MOISTURE FROM THE NW CARIBBEAN. A SURFACE TROUGH IS OVER THE BAY OF CAMPECHE WATERS WITH AXIS ALONG 21N93W TO 14N94W WITH ISOLATED SHOWERS AND TSTMS AHEAD OF IT S OF 20N. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ASSOCIATED WITH TWO FORMER TROUGHS ARE N OF 26N E OF 87W. HAZE AND FOG CONTINUE TO BE REPORTED IN THE NW GULF N OF 27 W OF 90W. SURFACE RIDGING WILL CONTINUE TO BE THE DOMINANT FEATURE DURING THE NEXT THREE DAYS.

CARIBBEAN SEA...

BROAD SURFACE HIGH PRESSURE ACROSS THE ATLANTIC CONTINUES TO EXTEND S INTO THE NORTHERN AND CENTRAL CARIBBEAN...THUS SUPPORTING A TIGHTER PRESSURE GRADIENT IN THE SW BASIN...RESULTING IN NE TO E WINDS OF 20 TO 25 KT FROM 11N TO 13N BETWEEN 73W AND 77 WITH SEAS UP TO 9 FT. ELSEWHERE...TRADES OF OF 15 KT AND SEAS LESS THAN 8 FT DOMINATE. SSMI TPW IMAGERY SHOW MODERATE LOW LEVEL MOISTURE OVER THE NW BASIN...WHICH ALONG WITH TROUGHING ALOFT SUPPORT ISOLATED SHOWERS AND TSTMS OVER WESTERN CUBA AND ALONG SOUTHERN COASTAL WATERS. SIMILAR CONVECTION IS OVER SOUTHERN HAITI ADJACENT WATERS. SHALLOW MOISTURE OVER THE NE CARIBBEAN SUPPORTS ISOLATED SHOWERS OVER PUERTO RICO AND NORTHERN LESSER ANTILLES. FAIR WEATHER IS ELSEWHERE BEING SUPPORTED BY DEEP LAYER DRY AIR. NO SIGNIFICANT CHANGES ARE EXPECTED IN THE NEXT TWO DAYS.


...HISPANIOLA...

UPPER LEVEL TROUGHING AND SHALLOW MOISTURE ACROSS THE SW ISLAND ENHANCE ISOLATED SHOWERS OVER SOUTHERN HAITI AND ADJACENT WATERS. DEEP LAYER DRY AIR IS OVER THE REMAINDER ISLAND AS DEPICTED BY SSMI TPW AND WATER VAPOR IMAGERY...THUS SUPPORTING FAIR WEATHER. SHOWERS AND THUNDERSTORMS ACTIVITY ARE EXPECTED DURING THE AFTERNOON AND EVENING HOURS THROUGH THURSDAY BEING ENHANCED BY OROGRAPHIC LIFTING AND DAYTIME HEATING AND SUPPORTED BY UPPER LEVEL TROUGHING.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL LOW ANCHORED NEAR 26N60W CONTINUE TO SUPPORT A SURFACE TROUGH WITH AXIS EXTENDING FROM 34N59W TO 23N60W. NUMEROUS MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 22N TO 32N BETWEEN 51W AND 59W. A TROPICAL WAVE IS W OF THE ITCZ. SEE THE TROPICAL WAVES SECTION ABOVE. N OF THE TROPICAL WAVE SCATTERED MODERATE CONVECTION IS FROM 11N TO 16N BETWEEN 32W AND 52W. ELSEWHERE SURFACE HIGH PRESSURE AND FAIR WEATHER PREVAILS. THE SURFACE TROUGH WILL CONTINUE TO DRIFT W TOWARDS THE SW N ATLC DURING THE NEXT THREE DAYS. SURFACE RIDGING WILL DOMINATE ELSEWHERE.

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

$$ NR

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