Tropical Weather Discussion
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000
AXNT20 KNHC 031053
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI JUL 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...

GALE-FORCE WINDS ARE PRESENT CURRENTLY FROM 11N TO 13N BETWEEN
74W AND 77W...IN THE COASTAL WATERS OF COLOMBIA. THE GALE-FORCE
WINDS ARE FORECAST UNTIL THE 48-HOUR TIME PERIOD IN THE 03/0600
UTC FORECAST. THE SEA HEIGHTS ARE FORECAST TO RANGE FROM 10 FEET
TO 15 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 23W/24W FROM 17N
SOUTHWARD...MOVING WESTWARD 10 TO 15 KNOTS. RAINSHOWERS ARE
POSSIBLE IN BROKEN LOW LEVEL CLOUDS...FROM 3N TO 10N BETWEEN
17W AND 26W.

AN ATLANTIC OCEAN TROPICAL WAVE HAS BEEN RE-POSITIONED IN ORDER
TO BE ALONG 39W/40W BASED ON LONG-TERM SATELLITE IMAGERY. THE
WAVE IS MOVING WESTWARD 15 KNOTS. CONVECTIVE PRECIPITATION...
RAINSHOWERS ARE POSSIBLE FROM THE EQUATOR TO 12N BETWEEN 30W AND
50W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 52W/53W FROM 15N
SOUTHWARD...MOVING WESTWARD 15 KNOTS. NO SIGNIFICANT DEEP
CONVECTIVE PRECIPITATION IS APPARENT.

AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 62W/63W FROM 19N
SOUTHWARD...MOVING WESTWARD 15 TO 20 KNOTS. RAINSHOWERS ARE
POSSIBLE WITH BROKEN LOW LEVEL CLOUDS...THAT ARE FROM 11N TO
18N BETWEEN 58W AND 70W.

ONE WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 84W/85W FROM
19N SOUTHWARD...MOVING WESTWARD 15 TO 20 KNOTS. THE SOUTHERN
PART OF THE WAVE IS INLAND...PASSING THROUGH EASTERN HONDURAS...
NICARAGUA...AND COSTA RICA. THIS WAVE IS MOVING THROUGH THE
WESTERN PART OF AN UPPER LEVEL TROUGH. UPPER LEVEL NORTHWESTERLY
WIND FLOW IS MOVING THROUGH THE AREA OF THE WAVE.

A SECOND WESTERN CARIBBEAN SEA TROPICAL WAVE IS INLAND...ALONG
90W FROM 20N SOUTHWARD...FROM THE YUCATAN PENINSULA TO
GUATEMALA...AND BEYOND EL SALVADOR INTO THE EASTERN PACIFIC
OCEAN. THIS WAVE IS MOVING THROUGH THE WESTERN PART OF AN UPPER
LEVEL TROUGH. UPPER LEVEL NORTHWESTERLY WIND FLOW IS MOVING
THROUGH THE AREA OF THE WAVE. A SEPARATE UPPER LEVEL TROUGH
SPANS THE NORTHERNMOST PART OF THE YUCATAN PENINSULA...FROM 20N
NORTHWARD.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF GUINEA-
BISSAU NEAR 12N16W TO 9N22W. THE ITCZ CONTINUES FROM 8N24W TO
7N30W AND 7N39W. CONVECTIVE PRECIPITATION...CONVECTIVE
PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM THE EQUATOR TO 12N
BETWEEN 30W AND 50W.

...DISCUSSION...

FROM THE GULF OF MEXICO INTO THE NORTHWESTERN CORNER OF THE
CARIBBEAN SEA...

BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS THE
GULF OF MEXICO. A TROUGH EXTENDS FROM THE SOUTHEASTERN CORNER OF
THE AREA TO A 22N91W CYCLONIC CIRCULATION CENTER...THAT IS JUST
OFF THE NORTHWESTERN COAST OF THE YUCATAN PENINSULA. CONVECTIVE
PRECIPITATION...BROKEN TO OVERCAST MULTILAYERED CONVECTIVE
DEBRIS CLOUDS AND POSSIBLY REMNANT RAINSHOWERS COVER THE AREA
FROM CENTRAL GUATEMALA TO 23N BETWEEN 86W AND 93W. ISOLATED
MODERATE AROUND LA ISLA DE LA JUVENTUD OF CUBA...AND IN THE
STRAITS OF FLORIDA.

A SURFACE RIDGE PASSES THROUGH CENTRAL FLORIDA FROM THE ATLANTIC
OCEAN...TOWARD AND BEYOND THE UPPER TEXAS GULF COAST.

THE REST OF THE CARIBBEAN SEA...

UPPER LEVEL SOUTHWESTERLY WIND FLOW IS TO THE EAST OF THE LINE
THAT RUNS FROM SOUTH CENTRAL COASTAL HISPANIOLA...TO THE COAST
OF COLOMBIA NEAR 11N75W.

EASTERLY WIND FLOW...FROM 600 MB TO 800 MB...SPANS MUCH OF THE
ENTIRE AREA OF THE CARIBBEAN SEA...MORE PROMINENTLY...FROM 10N
TO 20N BETWEEN 60W AND 70W...AND FROM 16N SOUTHWARD BETWEEN 78W
AND CENTRAL AMERICA.

AN UPPER LEVEL TROUGH EXTENDS FROM JAMAICA...SOUTHWESTWARD...
INTO THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA.

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

...HISPANIOLA...

MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW SURROUNDS
HISPANIOLA...THANKS TO THE ATLANTIC OCEAN-TO-HISPANIOLA TROUGH
THAT EXTENDS FROM A 26N69W CYCLONIC CIRCULATION CENTER...TO
HISPANIOLA. EASTERLY WIND FLOW...FROM 600 MB TO 800 MB...COVERS
THE ATLANTIC OCEAN FROM 20N TO 25N BETWEEN 70W AND 75W.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT SOUTHWESTERLY WIND
FLOW WILL CROSS HISPANIOLA FOR MOST OF THE NEXT 48 HOURS. THE
WIND DIRECTION WILL CHANGE TO SOUTHWESTERLY/WESTERLY AND FINALLY
TO WESTERLY/NORTHWESTERLY DURING THE LAST FEW 6-HOUR TIME
INTERVALS OF THE OVERALL 48-HOUR FORECAST PERIOD. THE GFS MODEL
FORECAST FOR 500 MB SHOWS THAT AN INVERTED TROUGH WILL MOVE
ACROSS HISPANIOLA FOR ABOUT THE FIRST 24 HOURS OF THE FORECAST
PERIOD...GIVING EASTERLY WIND FLOW. THE INVERTED TROUGH WILL
MOVE INTO THE WINDWARD PASSAGE DURING THE NEXT 24 HOURS...GIVING
SOUTHEASTERLY WIND FLOW TO HISPANIOLA...BEING ON THE EASTERN
SIDE OF THE INVERTED TROUGH. THE GFS MODEL FORECAST FOR 700 MB
SHOWS THAT EAST-TO-SOUTHEAST WIND FLOW WILL CROSS HISPANIOLA FOR
THE NEXT 48 HOURS. AN INVERTED TROUGH DEVELOPS DURING THE SECOND
HALF OF THE OVERALL 48-HOUR FORECAST PERIOD...EVENTUALLY
SETTLING IN THE WINDWARD PASSAGE.

THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH BERMUDA TO
30N67W...TO A 26N69W CYCLONIC CIRCULATION CENTER...TO
HISPANIOLA. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM
FROM 23N NORTHWARD BETWEEN 50W AND 80W.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 28N44W. CYCLONIC WIND FLOW COVERS THE AREA FROM 22N TO 31N
BETWEEN 38W AND 50W.

A SURFACE RIDGE EXTENDS FROM THE MADEIRA ARCHIPELAGO...TO
30N30W...TO A 1028 MB HIGH PRESSURE CENTER THAT IS NEAR
34N48W...31N62W...BEYOND CENTRAL FLORIDA...INTO THE GULF OF
MEXICO.

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

$$
MT


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