Tropical Weather Discussion
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000
AXNT20 KNHC 040000
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN MAY 03 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO
03N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
03N16W TO 02N33W TO THE NORTHERN COAST OF BRAZIL NEAR 01S50W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 03S TO
11N E OF 20W. SCATTERED MODERATE CONVECTION IS FROM 06S TO 05N W
OF 20W.

...DISCUSSION...

GULF OF MEXICO...

A SURFACE RIDGE EXTENDS FROM NOVA SCOTIA SW ALONG THE SE CONUS
INTO THE GULF WITH A 1023 MB HIGH CENTERED OVER NORTH CAROLINA
ADJACENT WATERS NEAR 32N75W. AN UPPER LEVEL TROUGH EXTENDING
FROM WEST VIRGINIA SOUTHWARD ACROSS THE EASTERN GULF TO A BASE
OVER THE NW CARIBBEAN SUPPORT A WEAKNESS IN THE SURFACE RIDGE
ANALYZED AS A SURFACE TROUGH FROM 29N86W TO 23N84W. LOW-LEVEL
MOISTURE CONVERGENCE NEAR THE TAIL OF THE TROUGH AND FORCING BY
THE UPPER TROUGH SUPPORT SCATTERED MODERATE CONVECTION AND
ISOLATED TSTMS FROM 23N TO 26N BETWEEN 83W AND 86W. SURFACE HIGH
PRESSURE ALONG WITH DEEP LAYER DRY AIR AS DEPICTED BY WATER
VAPOR AND SSMI TPW IMAGERY SUPPORT FAIR WEATHER ELSEWHERE. WINDS
ACROSS THE BASIN ARE MAINLY FROM THE E-SE IN THE RANGE OF 10 TO
15 KT...EXCEPT SE OF THE TROUGH AXIS AND THE FLORIDA STRAITS
WHERE WINDS CAN REACH A MAXIMUM OF 20 KT. SURFACE RIDGING WILL
BE THE DOMINANT FEATURE OVER THE BASIN DURING THE NEXT TWO DAYS.
THE SURFACE TROUGH WILL MOVE OVER WESTERN GULF WATERS MONDAY
WHERE IT IS EXPECTED TO DISSIPATE. LOW PRESSURE STARTS TO BUILD
OVER THE WESTERN BASIN TUESDAY MORNING.

CARIBBEAN SEA...

AN UPPER LEVEL TROUGH OVER THE NW ATLC WATERS CONTINUE TO
SUPPORT A LOW PRESSURE SYSTEM FROM WHICH A STATIONARY FRONT
EXTENDS FROM 31N54W SW TO 25N64W TO EASTERN CUBA NEAR 20N74W
INTO THE NW CARIBBEAN WHERE IT STARTS TO DISSIPATE. THE BASE OF
AN UPPER LEVEL TROUGH EXTENDING SOUTHWARD FROM WEST VIRGINIA AND
AN UPPER RIDGE ANCHORED OVER THE CENTRAL ATLC ARE GENERATING
DIFFLUENT FLOW ACROSS THE NW CARIBBEAN...WHICH ALONG WITH
ABUNDANT LOW LEVEL MOISTURE SUPPORT SCATTERED SHOWERS AND TSTMS
N OF 18N BETWEEN 75W AND 85W. ISOLATED SHOWERS ARE ELSEWHERE S
OF 18N BETWEEN 81W AND 84W. SHALLOW MOISTURE IS ENTERING THE FAR
EASTERN BASIN...THUS ENHANCING ISOLATED SHOWERS ACROSS THE
LESSER ANTILLES AND OVER EASTERN PUERTO RICO ADJACENT WATERS. AN
ACTIVE MONSOON TROUGH OVER THE EAST PACIFIC WATERS IS ENHANCING
SHOWERS OVER THE SW BASIN S OF 12N BETWEEN 79W AND 83W. THE
REMAINDER BASIN IS UNDER THE INFLUENCE OF THE UPPER LEVEL RIDGE
AND DEEP LAYER DRY AIR THAT SUPPORT FAIR WEATHER. TRADES OF 10
TO 15 KT ARE EAST OF THE DISSIPATING STATIONARY
FRONT...INCREASING TO 20 KT ALONG THE COAST OF NORTHERN SOUTH
AMERICA. NORTHERLY WIND OF 10 KT DOMINATE OVER THE NW BASIN WEST
OF THE DISSIPATING BOUNDARY. THE DISSIPATING STATIONARY FRONT
WILL CONTINUE TO WEAKEN...LEAVING A SURFACE TROUGH THAT WILL
DRIFT WESTWARD TOWARDS THE YUCATAN PENINSULA MONDAY MORNING.

...HISPANIOLA...

LOW LEVEL MOISTURE ASSOCIATED WITH A STATIONARY FRONT EXTENDING
FROM THE CENTRAL ATLC SW TO EASTERN CUBA AND THEN DISSIPATING
OVER THE NW CARIBBEAN SUPPORTS CLOUDINESS ACROSS HAITI AND
WESTERN DOMINICAN REPUBLIC. LOW LEVEL MOISTURE CONVERGENCE
ASSOCIATED WITH THE FRONT ALONG WITH A DIFFLUENT ENVIRONMENT
ALOFT MAY ENHANCE ISOLATED SHOWERS TONIGHT ACROSS THE WINDWARD
PASSAGE AND THE REGIONS AFOREMENTIONED. THE PORTION OF THE FRONT
OVER THE CARIBBEAN WILL CONTINUE TO WEAKEN LEAVING A SURFACE
TROUGH TO MOVE OVER THE YUCATAN PENINSULA TUESDAY MORNING. THE
PORTION OF THE FRONT N OF EASTERN CUBA WILL START TO DISSIPATE
MONDAY MORNING. LINGERING MOISTURE ASSOCIATED WITH THIS BOUNDARY
MAY ENHANCE SHOWERS ACROSS THE WESTERN ISLAND AND
ADJACENT WATERS THROUGH MONDAY EVENING.

ATLANTIC OCEAN...

AN UPPER LEVEL TROUGH OVER THE NW ATLC WATERS CONTINUE TO
SUPPORT A LOW PRESSURE SYSTEM FROM WHICH A STATIONARY FRONT
EXTENDS FROM 31N54W SW TO 25N64W TO EASTERN CUBA NEAR 20N74W
INTO THE NW CARIBBEAN WHERE IT STARTS TO DISSIPATE. THE BASE OF
AN UPPER LEVEL TROUGH EXTENDING SOUTHWARD FROM WEST VIRGINIA
INTO THE NW CARIBBEAN AND AN UPPER RIDGE ANCHORED OVER THE
CENTRAL ATLC ARE GENERATING DIFFLUENT FLOW ACROSS PORTIONS OF
THE SW N ATLC...WHICH ALONG WITH ABUNDANT LOW LEVEL MOISTURE
SUPPORT SCATTERED SHOWERS WITHIN 360 NM W OF THE
FRONT...INCLUDING THE CENTRAL AND SOUTHERN BAHAMAS. A SURFACE
LOW PRESSURE SYSTEM IS E OF THE CANARY ISLANDS FROM WHICH A COLD
FRONT EXTENDS ENTERING THE CENTRAL ATLC WATERS ALONG 30N27W TO
28N35W TO 29N39W WITH NO CONVECTION ASSOCIATED WITH IT. THE
REMAINDER BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE BEING
ANCHORED BY A 1021 MB HIGH NEAR 25N49W. THE FRONT WILL DISSIPATE
OVER THE NW CARIBBEAN AND WILL START TO WEAKEN OVER THE SW N
ATLC BY MONDAY MORNING...LEAVING AN ELONGATED AREA OF LOW
PRESSURE OVER THE NORTHERN BAHAMAS BY TUESDAY MORNING. RIDGING
WILL DOMINATE ELSEWHERE.

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

$$
NR



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