Tropical Weather Discussion
Issued by NWS

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000
AXNT20 KNHC 282343
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN JUN 28 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.

...SPECIAL FEATURES...

...GALE IN THE CARIBBEAN...
A GALE WARNING WILL GO INTO EFFECT FOR THE SW CARIBBEAN FROM
11.5N-13.5N BETWEEN 73W-77W OVERNIGHT TONIGHT THROUGH MON
AFTERNOON AND WILL PULSE AGAIN MON NIGHT AND TUE NIGHT. THESE
WINDS ARE GENERATED BY A TIGHT PRESSURE GRADIENT BETWEEN THE
SURFACE RIDGE OVER THE W ATLC AND THE LOWER PRESSURE OVER SOUTH
AMERICA. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO
HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 47W/48W FROM
7N-15N MOVING W-NW AT 25 KT OVER THE PAST 24 HOURS. THE TOTAL
PRECIPITABLE WATER IMAGERY SHOWS THE WAVE ALONG THE LEADING EDGE
OF A LOW AMPLITUDE SURGE OF DEEP MOISTURE. NO ASSOCIATED DEEP
CONVECTION.

TROPICAL WAVE IN CENTRAL CARIBBEAN EXTENDS ALONG 72W/73W FROM
OVER S HAITI NEAR 19N TO OVER COLOMBIA MOVING W-NW NEAR 35 KT
OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY
SHOWS THE WAVE IS AHEAD OF A HIGH AMPLITUDE SURGE OF MODERATE/
DEEP MOISTURE. NO ASSOCIATED DEEP CONVECTION.

TROPICAL WAVE IN THE W CARIBBEAN EXTENDS ALONG 81W/82W S OF 17N
TO ACROSS PANAMA MOVING W-SW NEAR 30 KT OVER THE PAST 24 HOURS.
THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED
WITHIN AN AREA OF DEEP MOISTURE THAT COVERS THE CARIBBEAN W OF
76W. NO ASSOCIATED DEEP CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC
NEAR 12N16W ALONG 8N22W TO 8N35W WHERE THE ITCZ BEGINS AND
CONTINUES ALONG 8N42W 6N49W TO SOUTH AMERICA NEAR 5N53W. NO
SIGNIFICANT DEEP CONVECTION.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER TROUGH COVERS THE E CONUS TO THE N GULF COAST
SUPPORTING A FRONTAL BOUNDARY WELL INLAND AND GENERATING
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ALONG THE N GULF COAST
AND IN THE GULF WATERS TO 27N BETWEEN FLORIDA AND TEXAS. THE
GULF WATERS IS UNDER A LARGE UPPER LOW THAT IS CENTERED OVER THE
W GULF NEAR 24N93W AND GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS FROM 23N-27N BETWEEN 86W-93W. A WEAK SURFACE RIDGE
EXTENDS FROM THE W ATLC ACROSS S FLORIDA COVERING THE GULF WITH
A WEAK 1020 MB HIGH NEAR 26N88W. A WEAK DIURNAL SURFACE TROUGH
IS ALONG THE W COAST OF THE YUCATAN PENINSULA. THIS WEAK SURFACE
TROUGH WILL DEVELOP ALONG THE NW COAST OF THE YUCATAN PENINSULA
EACH EVENING MOVING NW LATE EACH NIGHT THROUGH EARLY EACH
MORNING AND DISSIPATING OVER THE SW GULF BY EARLY AFTERNOON. THE
SURFACE RIDGE WILL PERSIST THROUGH MON THEN SHIFT N MON NIGHT TO
A POSITION FROM CENTRAL FLORIDA TO NE TEXAS WHERE IT WILL
MEANDER THROUGH MID WEEK.

CARIBBEAN SEA...
THE UPPER LOW OVER THE GULF OF MEXICO COVERS THE NW CARIBBEAN N
OF 18N W OF 83W. AN UPPER RIDGE EXTENDS THROUGH THE W ATLC
ACROSS CENTRAL CUBA TO NEAR 17N81W WHILE THE UPPER TROUGH OVER
REMAINDER OF THE W ATLC AND CENTRAL ATLC DIPS S OVER THE NE
CARIBBEAN LEAVING THE S CARIBBEAN WITH NEAR ZONAL WESTERLY FLOW
ALOFT. ISOLATED SHOWERS/THUNDERSTORMS DOT THE GULF OF HONDURAS S
OF 18N W OF 83W. AFTERNOON/EVENING SHOWERS/THUNDERSTORMS HAVE
DEVELOPED INLAND OVER CUBA AND W HISPANIOLA. THIS IS LEAVING THE
REMINDER OF THE CARIBBEAN WITH FAIR WEATHER THIS EVENING. A
PERSISTENT W ATLC SURFACE RIDGE WILL MAINTAIN STRONG TO NEAR
GALE TRADE WINDS ACROSS THE S/CENTRAL CARIBBEAN PULSING TO GALE
FORCE EACH NIGHT THROUGH MID WEEK. TROPICAL WAVE IN THE W
CARIBBEAN WILL MOVE OVER CENTRAL AMERICA AND OUT OF THE
DISCUSSION AREA BY EARLY MON. CENTRAL CARIBBEAN TROPICAL WAVE
WILL MOVE INTO W CARIBBEAN BY MON NIGHT BEFORE MOVING W OF THE
AREA TUE. A THIRD TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN
MON NIGHT THEN INTO THE CENTRAL CARIBBEAN BY TUE AND THE W
CARIBBEAN BY MID WEEK.

...HISPANIOLA...
AFTERNOON/EVENING SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND NE
DOMINICAN REPUBLIC AND N HAITI THIS EVENING LEAVING THE
REMAINDER OF THE ISLAND WITH CLEAR SKIES. THE TROPICAL WAVE WILL
MOVE AWAY FROM THE ISLAND LATER TONIGHT. LINGERING MOISTURE WILL
MOVE OUT EARLY ON MON LEAVING THE CHANCE FOR ISOLATED SHOWERS/
THUNDERSTORMS FOR MON AND TUE AFTERNOON. TUE NIGHT MOISTURE WILL
AGAIN INCREASE WITH THE APPROACH OF THE NEXT TROPICAL WAVE
INCREASING THE CHANCES OF MORE WIDESPREAD SHOWERS/THUNDERSTORMS
THROUGH MID WEEK.

ATLANTIC OCEAN...
THE UPPER TROUGH AND FRONT OVER THE E CONUS IS GENERATING
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS W OF LINE FROM DAYTONA
BEACH FLORIDA TO BEYOND 32N78W. A NARROW UPPER RIDGE IS TO THE E
EXTENDING THROUGH 32N73W ALONG 28N78W TO ACROSS CENTRAL CUBA
INTO THE W CARIBBEAN. THIS IS PROVIDING DIFFLUENT FLOW TO
GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60/75
NM OF LINE FROM ANDROS ISLAND ALONG 28N77W TO BEYOND 32N73W. A
BROAD BUT WEAK UPPER TROUGH COVERS THE REMAINDER OF THE W ATLC
AND INTO THE CENTRAL ATLC WITH A PAIR OF UPPER LOWS...ONE N OF
HISPANIOLA NEAR 24N70W AND A SECOND NEAR 23N56W. ISOLATED
SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 22N-28N
BETWEEN 66W-74W INCLUDING THE TURKS AND CAICOS. A BROAD E/W
SURFACE RIDGE DOMINATES THE ATLC BASIN WITH A 1026 MB HIGH NEAR
29N57W AND A 1024 MB HIGH NEAR 30N31W. NOAA/NESDIS AEROSOL
PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT A
LARGE DENSE PLUMB OF AEROSOLS OR SAHARAN DUST COVERS THE AREA
FROM 15N-30N BETWEEN 52W-68W INCLUDING THE NE CARIBBEAN. A
SECOND WEAKER PLUMB COVERS THE TROPICS S OF 26N E OF 45W. THE
SURFACE RIDGE WILL PERSIST THROUGH MID WEEK THEN SHIFT N THROUGH
THE END OF THE WEEK.

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

$$
PAW



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