Tropical Weather Discussion
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000
AXNT20 KNHC 301116
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUN 30 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
1015 UTC.

...SPECIAL FEATURES...

GALE-FORCE WINDS ARE PRESENT NOW...IN THE COASTAL WATERS OF
COLOMBIA...FROM 11.5N TO 13N BETWEEN 74W AND 77W...AND THOSE
GALE-FORCE WINDS WILL CONTINUE FOR THE NEXT 12 HOURS. SEA
HEIGHTS ARE FORECAST TO RANGE FROM 12 FEET TO 18 FEET. PLEASE
READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE
OFFSHORE FORECAST...MIAOFFNT3/FZNT23 KNHC...FOR MORE DETAILS.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 21W FROM 13N
SOUTHWARD...MOVING WESTWARD 10 TO 15 KNOTS. ITCZ-RELATED
CONVECTIVE PRECIPITATION IS NEARBY.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 14N57W 11N59W 7N60W IN
GUYANA...MOVING WESTWARD 20 TO 25 KNOTS. CONVECTIVE
PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM 5N TO 18N BETWEEN
50W AND 60W.

AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 19N62W 15N66W
10N67W...MOVING WESTWARD 30 KNOTS. A MIDDLE LEVEL TO UPPER LEVEL
TROUGH IS ALONG 27N59W 22N65W 17N69W. CONVECTIVE
PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG
WITHIN 30 NM TO 45 NM ON EITHER SIDE OF 23N64W 20N67W 17N70W.
ISOLATED MODERATE FROM 16N TO 19N BETWEEN 63W AND 67W.

A TROPICAL WAVE IS INLAND...ALONG 85W/86W...FROM 17N
SOUTHWARD...MOVING WESTWARD 20 TO 25 KNOTS. IT PASSES THROUGH
CENTRAL HONDURAS...WESTERN NICARAGUA...AND THE WESTERN COASTAL
AREAS OF COSTA RICA. CONVECTIVE PRECIPITATION...THE NUMEROUS
STRONG FROM 9N TO 11N BETWEEN 84W AND 86W IN THE EASTERN PACIFIC
OCEAN SIDE COASTAL PLAINS AND COASTAL WATERS OF COSTA RICA FROM
SIX HOURS AGO HAS WEAKENED AND DISSIPATED. SCATTERED STRONG IS
IN THE COASTAL PLAINS OF COSTA RICA AND PANAMA BETWEEN 80W AND
THE BORDER OF COSTA RICA AND NICARAGUA. THAT PRECIPITATION MAY
BE MORE RELATED TO BROAD LOW PRESSURE IN GENERAL IN THE
SOUTHWESTERN CORNER OF THE CARIBBEAN SEA.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF GUINEA-
BISSAU NEAR 13N17W TO 10N20W. THE ITCZ STARTS FROM 8N23W TO
6N24W TO 6N34W 4N36W AND 3N40W. CONVECTIVE PRECIPITATION...
ISOLATED MODERATE TO LOCALLY STRONG WITHIN 150 NM ON EITHER SIDE
OF 9N14W 8N25W 6N36W 5N46W.

...DISCUSSION...

THE GULF OF MEXICO...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM THE GREAT
LAKES AREA OF THE U.S.A. TO THE UPPER TEXAS GULF COAST...TO
26N96W OFF THE COAST OF THE DEEP SOUTH OF TEXAS. RAINSHOWERS AND
THUNDERSTORMS COVER THE AREAS FROM ALABAMA AND MISSISSIPPI...
TO SOUTHEASTERN ARKANSAS...INTO NORTH CENTRAL TEXAS.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 23N86W AT THE NORTHERN PART OF THE YUCATAN CHANNEL. THIS
CYCLONIC CENTER IS COMPARATIVELY WEAKER AND LESS WELL-DEFINED
NOW THAN IT WAS SIX HOURS AGO. CYCLONIC WIND FLOW IS WITHIN A
RADIUS OF 120 NM TO 150 NM AWAY FROM THE 23N86W CYCLONIC CENTER.

AN UPPER LEVEL RIDGE IS IN MEXICO. UPPER LEVEL NORTHWESTERLY
WIND FLOW IS MOVING FROM MEXICO INTO THE SOUTHWESTERN CORNER OF
THE GULF OF MEXICO. 600 MB TO 800 MB LEVEL SOUTHEASTERLY WIND
FLOW IS MOVING FROM THE NORTHEASTERN CORNER OF THE CARIBBEAN
SEA...ACROSS THE YUCATAN PENINSULA...INTO THE SOUTHWESTERN
CORNER OF THE GULF OF MEXICO. A DIURNAL SURFACE TROUGH HAS
EMERGED FROM THE YUCATAN PENINSULA...AND NOW IT IS ALONG 23N92W
18N94W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG ALONG THE
MEXICO COAST FROM 21N TO 24N BETWEEN 96W AND 98W. IN THE ISTHMUS
OF TEHUANTEPEC. BROKEN MULTILAYERED CLOUDS COVER MUCH OF THE
REST OF THE GULF OF MEXICO. RAINSHOWERS ARE POSSIBLE ELSEWHERE
IN THIS CLOUDINESS.

SURFACE ANTICYCLONIC WIND FLOW COVERS THE GULF OF MEXICO FROM
24N NORTHWARD. THE ANTICYCLONIC WIND FLOW IS MOVING AROUND A
1019 MB HIGH PRESSURE CENTER THAT IS NEAR 27N89W.

THE CARIBBEAN SEA...

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 23N86W AT THE NORTHERN PART OF THE YUCATAN CHANNEL.
CYCLONIC WIND FLOW IS WITHIN A RADIUS OF 120 NM TO 150 NM AWAY
FROM THE CYCLONIC CENTER. UPPER LEVEL NORTHWESTERLY WIND FLOW
COVERS THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N67W TO
25N67W 19N68W...ACROSS THE EASTERNMOST SECTIONS OF THE DOMINICAN
REPUBLIC AND THROUGH THE MONA PASSAGE...TO 16N69W IN THE
CARIBBEAN SEA.

UPPER LEVEL WESTERLY WIND FLOW IS FROM 17N SOUTHWARD...MOVING
FROM CENTRAL AMERICA ACROSS THE EASTERN CARIBBEAN SEA ISLANDS.

EASTERLY WIND FLOW...FROM 350 MB TO 500 MB TO 800 MB...SPANS THE
CARIBBEAN SEA...FROM THE GREATER ANTILLES SOUTHWARD. A MIDDLE
LEVEL TO UPPER LEVEL TROUGH IS ALONG 17N66W 20N60W 26N57W.

TWO TROPICAL WAVES ARE MOVING THROUGH THE AREA. PLEASE REFER TO
THE TROPICAL WAVES SECTION FOR DETAILS.

...HISPANIOLA...

MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW SURROUNDS
HISPANIOLA...THANKS TO THE 32N67W TO 16N69W TROUGH.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT BROAD THE CURRENT
ATLANTIC OCEAN-TO-CARIBBEAN SEA TROUGH WILL PASS DIRECTLY ACROSS
HISPANIOLA. A NORTHWEST-TO-SOUTHEAST ORIENTED INVERTED TROUGH
EVENTUALLY WILL MOVE TO A POSITION THAT IS DIRECTLY ON TOP OF
HISPANIOLA AT THE END OF THE 48-HOUR FORECAST PERIOD. THE GFS
MODEL FORECAST FOR 500 MB SHOWS THAT NORTHEASTERLY WIND FLOW
WILL CROSS HISPANIOLA AT THE START OF THE FORECAST PERIOD. AN
INVERTED TROUGH WILL MOVE ACROSS HISPANIOLA FROM 6 HOURS INTO
THE FORECAST PERIOD UNTIL 30 HOURS INTO THE FORECAST PERIOD.
SOUTHERLY WIND FLOW WILL CONTINUE FOR THE SECOND DAY. THE GFS
MODEL FORECAST FOR 700 MB SHOWS THAT NORTHEASTERLY-TO-EASTERLY
WIND FLOW WILL CROSS HISPANIOLA AT THE START OF THE FIRST 24-
HOUR PERIOD. AN INVERTED TROUGH WILL MOVE ACROSS HISPANIOLA
DURING THE REST OF THE FIRST DAY OF THE 48-HOUR FORECAST PERIOD.
SOUTHEASTERLY WIND FLOW WILL CONTINUE FOR DAY TWO.

THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N67W TO
25N67W 19N68W...ACROSS THE EASTERNMOST SECTIONS OF THE DOMINICAN
REPUBLIC AND THROUGH THE MONA PASSAGE...TO 16N69W IN THE
CARIBBEAN SEA. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO
ISOLATED STRONG FROM 25N TO 29N BETWEEN 74W AND 77W...AND FROM
31N TO 33N BETWEEN 73W AND 75W. RAINSHOWERS ARE POSSIBLE STILL
FROM 29N TO 33N BETWEEN 66W AND 70W.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N22W TO
28N28W AND 24N40W. THE TROUGH SUPPORTS A DISSIPATING COLD FRONT
THAT PASSES THROUGH 32N26W TO 29N40W AND 28N50W. BROKEN TO
OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE WITHIN
180 NM TO THE NORTH OF THE LINE THAT PASSES THROUGH 32N23W TO
27N40W 25N60W.

A SURFACE RIDGE PASSES THROUGH 32N16W TO 27N30W AND 23N43W. A
SECOND SURFACE RIDGE EXTENDS FROM A 1026 MB HIGH PRESSURE CENTER
THAT IS NEAR 33N56W TO 27N64W...ACROSS THE BAHAMAS...ACROSS
CENTRAL CUBA...TO 21N81W IN THE CARIBBEAN SEA JUST OFF THE
WESTERN COAST OF CUBA.

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

$$
MT


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