Tropical Weather Discussion
Issued by NWS

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547
AXNT20 KNHC 162338
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT MAY 16 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
2315 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC
NEAR 10N14W TO 5N20W WHERE THE ITCZ BEGINS AND CONTINUES ALONG
4N28W 2N34W 2N41W TO 3N49W. CLUSTERS OF SCATTERED MODERATE/
ISOLATED STRONG CONVECTION ARE FROM 4N TO S OF THE EQUATOR E OF
5W ACROSS THE PRIME MERIDIAN...FROM 6N-8N E OF 17W TO INLAND
OVER N LIBERIA AND SIERRA LEONE...AND FROM 1N-5N BETWEEN 16W-
25W. A SURFACE TROUGH EXTENDS FROM 8N51W TO JUST OFF THE COAST
OF SOUTH AMERICA NEAR 3N51W WITH CLUSTERS OF SCATTERED MODERATE
CONVECTION WITHIN 60 NM E AND 120 NM W OF THE TROUGH AXIS.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS A RIDGE
AXIS ACROSS S MEXICO NEAR VERACRUZ TO 24N91W WITH A SECOND BROAD
UPPER RIDGE EXTENDING FROM TAMPA BAY FLORIDA TO OVER THE E CONUS
TO THE GREAT LAKES. A CUTOFF UPPER LOW IS IN THE NW CARIBBEAN
COVERING THE SE GULF OF MEXICO AND GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS INLAND AND WITHIN 45 NM ALONG THE N COAST
OF CUBA AND WITHIN 90 NM OF THE W TIP CUBA IN THE YUCATAN
CHANNEL. AT THE SURFACE IS A SURFACE RIDGE THAT EXTENDS FROM THE
W ATLC OVER THE SE CONUS ALONG THE N GULF COAST COVERING THE
GULF. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS HAVE DEVELOPED
INLAND ALONG THE W COAST OF FLORIDA BETWEEN NAPLES AND TAMPA BAY
AND ARE DRIFTING INTO THE GULF WATERS. THE SURFACE RIDGE IS
GIVING THE GULF SOUTHERLY RETURN FLOW AND IS GENERATING ISOLATED
SHOWERS N OF 26N BETWEEN 92W-96W TO INLAND OVER LOUISIANA AND E
TEXAS. THIS SOUTHERLY FLOW WILL CONTINUE THROUGH MON. A SURFACE
HIGH WILL DEVELOP OVER THE NE GULF MON NIGHT AND THEN MEANDER
OVER NE GULF THROUGH THU.

CARIBBEAN SEA...
A CUTOFF UPPER LOW IS IN THE NW CARIBBEAN OFF CUBA NEAR 21N83W
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND
WITHIN 45 NM ALONG THE S COAST OF CUBA AND INTO THE YUCATAN
CHANNEL E OF 86W. AN UPPER RIDGE COVERS THE E CARIBBEAN WITH THE
AXIS ALONG 68W. THIS UPPER RIDGE IS ADVECTING TROPICAL MOISTURE
ACROSS PANAMA AND COSTA RICA GENERATING SCATTERED TO NUMEROUS
SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE SW CARIBBEAN S OF 12N
BETWEEN COLOMBIA AND NICARAGUA. THE EASTERLY TRADE WINDS ARE
GENERATING AFTERNOON/EVENING ISOLATED SHOWERS AND POSSIBLE
ISOLATED THUNDERSTORMS ACROSS THE REMAINDER OF CUBA...PUERTO
RICO...HISPANIOLA...AND JAMAICA. FRESH TO STRONG TRADE WINDS ARE
EXPECTED IN THE S/CENTRAL CARIBBEAN THROUGH SUN NIGHT. MODERATE
TO FRESH TRADE WINDS WILL PREVAIL ACROSS THE REMAINDER OF THE
AREA S OF 17N WITH MODERATE TRADE WINDS EXPECTED N OF 17N.

...HISPANIOLA...
AFTERNOON/EVENING ISOLATED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS ARE ACROSS THE ISLAND THIS EVENING. THE SW FLOW
ALOFT WILL BECOME MORE WESTERLY SUN AS THE UPPER LOW OVER THE NW
CARIBBEAN DISSIPATES. EXPECT DAYTIME HEATING AND OROGRAPHIC
LIFTING TO GENERATE AFTERNOON SHOWERS AND POSSIBLE THUNDERSTORMS
OVER THE NEXT DEW DAYS.

ATLANTIC OCEAN...
A SURFACE RIDGE COVERS THE W ATLC W OF 60W ANCHORED BY A 1028 MB
HIGH ABOUT 230 NM E OF WILMINGTON NORTH CAROLINA AND EXTENDS A
RIDGE AXIS OVER THE SE CONUS COVERING THE GULF OF MEXICO. A
BROAD UPPER TROUGH COVERS THE W INTO THE CENTRAL ATLC SUPPORTING
A COLD FRONT THAT ENTERS THE REGION NEAR 32N48W AND EXTENDS
ALONG 27N53W TO 24N57W WHERE IT DISSIPATES ALONG 23N64W TO
23N68W WHERE IT BECOMES A SURFACE TROUGH TO 26N71W. SCATTERED
SHOWERS ARE WITHIN 75 NM E OF THE COLD FRONT N OF 27N. A SECOND
RIDGE AXIS COVERS THE AREA E OF THE ABOVE FRONT ANCHORED BY A
1035 MB HIGH N OF THE AZORES. THE CENTRAL ATLC FRONT WILL
CONTINUE TO SHIFT EASTWARD. W ATLC HIGH PRESSURE WILL DRIFT
SOUTHWARD BETWEEN 70W AND 75W MON THROUGH WED.

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

$$
PAW



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