Tropical Weather Discussion
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000
AXNT20 KNHC 171044
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI APR 17 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
1030 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 06N10W SW
TO 01N18W WHERE THE ITCZ BEGINS AND CONTINUES ALONG THE EQUATOR
TO THE COAST OF NORTHERN BRAZIL NEAR 01S50W. SCATTERED MODERATE
CONVECTION AND TSTMS ARE FROM 02S TO 03N BETWEEN 18W AND 29W.
ISOLATED MODERATE CONVECTION AND TSTMS ARE FROM 07S TO 05N W OF
30W.

...DISCUSSION...

GULF OF MEXICO...

A 1016 MB LOW OVER GEORGIA ADJACENT WATERS EXTENDS A COLD FRONT
SW ACROSS NORTHERN-CENTRAL FLORIDA TO 28N83W WHERE IT
TRANSITIONS TO A DISSIPATING STATIONARY FRONT TO 30N88W. W OF
THE FRONT A SURFACE TROUGH EXTENDS FROM 29N88W TO 27N95W. LOW
LEVEL MOISTURE CONVERGENCE ASSOCIATED WITH THE TROUGH ALONG WITH
A DIFFLUENT ENVIRONMENT ALOFT ACROSS THE N-NE GULF SUPPORTS
SCATTERED MODERATE CONVECTION AND TSTMS N OF 27N E OF 94W.
SCATTERED SHOWERS AND TSTMS ARE OVER THE REMAINDER NW GULF. GOES-
GEO COLOR IMAGERY AND SURFACE OBSERVATIONS INDICATE THE PRESENCE
OF FOG OVER THE N-NW GULF N OF 26N W OF 88W. SURFACE RIDGING
OVER THE ATLC CONTINUE TO PROVIDE SE WIND FLOW OF 10 TO 15 KT
MAINLY S OF 28N. SURFACE RIDGING WILL BE THE DOMINANT FEATURE
OVER THE EASTERN BASIN THE NEXT THREE DAYS WHILE LOW PRESSURE
WILL CONTINUE W OF 90W. SHOWERS ACROSS THE NORTHERN GULF WILL
CONTINUE THROUGH FRIDAY NIGHT.

CARIBBEAN SEA...

A BROAD SURFACE RIDGE OVER THE ATLC OCEAN EXTENDS TO THE
NORTHERN CARIBBEAN WHILE LOWER PRESSURE DOMINATES ELSEWHERE S OF
14N. A SLIGHTLY TIGHTER PRESSURE GRADIENT IS OVER THE CENTRAL
CARIBBEAN ASSOCIATED WITH A 1010 MB LOW OVER N COLOMBIA...THUS
RESULTING IN TRADES OF 20 TO 25 KT S OF 15N BETWEEN 68W AND
78W...BEING THE STRONGEST WINDS ALONG THE COAST OF COLOMBIA.
ELSEWHERE TRADES OF 15 KT DOMINATE. SSMI TPW IMAGERY SHOW
SCATTERED PATCHES OF SHALLOW MOISTURE MOVING ACROSS THE NW AND
EASTERN BASIN...THUS SUPPORTING CLOUDINESS AND POSSIBLE ISOLATED
SHOWERS OVER THE LESSER ANTILLES...THE VIRGIN ISLANDS...CENTRAL
AND WESTERN HISPANIOLA AND THE NW CARIBBEAN N OF 17N. ISOLATED
SHOWERS ARE ON PANAMA AND COSTA RICA COASTAL WATERS. FAIR
WEATHER IS ELSEWHERE BEING SUPPORTED BY DRY AIR SUBSIDENCE FROM
ALOFT. NOT SIGNIFICANT CHANGES ARE EXPECTED DURING THE NEXT TWO
DAYS.

...HISPANIOLA...

A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE SW N ATLC S
ACROSS THE ISLAND TO NORTHERN VENEZUELA. SHALLOW MOISTURE ALONG
WITH LIFTING PROVIDED BY THE UPPER TROUGH SUPPORT CLOUDINESS
WITH POSSIBLE SCATTERED TO ISOLATED SHOWERS...MAINLY FOCUSED
OVER HAITI AND THE WINDWARD PASSAGE. SHOWERS ARE EXPECTED TO
CONTINUE THROUGH FRIDAY MORNING WHEN A DRY AIRMASS ENTERS THE
ISLAND PROVIDING FAIR WEATHER CONDITIONS FOR THE REMAINDER
WEEKEND.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL LOW OVER THE NORTH-CENTRAL ATLC EXTENDS
A TROUGH TO A BASE N OF 30N...THUS SUPPORTING A SURFACE LOW
PRESSURE SYSTEM FROM WHICH A COLD FRONT EXTENDS SW ENTERING THE
AREA OF DISCUSSION FROM 30N44W TO 27N57W TO 28N68W. A 1016 MB
LOW IS OVER GEORGIA ADJACENT WATERS FROM WHICH A COLD FRONT
EXTENDS SW TO CAPE CANAVERAL FLORIDA. ISOLATED SHOWERS ARE
WITHIN 100 NM EITHER SIDE OF THE COLD FRONT. SCATTERED SHOWERS
AND TSTMS ARE OVER THE SW N ATLC N OF 25N W OF 70W. SURFACE
RIDGING AND FAIR WEATHER DOMINATES ELSEWHERE.

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

$$
NR



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