Tropical Weather Discussion
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000
AXNT20 KNHC 020559
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU JUL 02 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURES...

GALE-FORCE WINDS ARE FORECAST AT 30 HOURS...BASED ON THE
FORECAST FOR 02/0000 UTC...IN THE COASTAL WATERS OF COLOMBIA...
FROM 11.5N TO 12.5N BETWEEN 74W AND 77W. THE SEA HEIGHTS ARE
FORECAST TO RANGE FROM 11 FEET TO 17 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 31W/32W FROM 12N
SOUTHWARD...MOVING WESTWARD 10 TO 15 KNOTS. A 1014 MB LOW
PRESSURE CENTER IS ALONG THE WAVE NEAR 10N. CONVECTIVE
PRECIPITATION...ISOLATED MODERATE FROM 5N TO 10N BETWEEN 31W AND
38W.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 46W/47W FROM 10N
SOUTHWARD...MOVING WESTWARD 10 TO 15 KNOTS. CONVECTIVE
PRECIPITATION...ISOLATED MODERATE TO LOCALLY STRONG FROM 9N TO
10N BETWEEN 40W AND 44W. BROKEN TO OVERCAST MULTILAYERED CLOUDS
AND OTHER POSSIBLE RAINSHOWERS COVER THE AREA FROM THE EQUATOR
TO 10N BETWEEN 42W AND 50W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 75W/76W FROM 19N
SOUTHWARD...PASSING BETWEEN HAITI AND JAMAICA...MOVING WESTWARD
20 KNOTS. UPPER LEVEL SOUTHWESTERLY WIND FLOW IS MOVING ACROSS
THE AREA OF THE WAVE FROM 15N SOUTHWARD. MIDDLE LEVEL TO UPPER
LEVEL EASTERLY WIND FLOW IS MOVING ACROSS THE AREA OF THE WAVE
FROM 13N TO 16N. 600 MB TO 800 MB LEVEL EASTERLY WIND FLOW
COVERS THE AREA THAT IS FROM 17N SOUTHWARD BETWEEN 78W AND
CENTRAL AMERICA. THE WAVE IS MOVING TOWARD THE AREA OF AN
ALREADY-EXISTING UPPER LEVEL TROUGH WHOSE CYCLONIC WIND FLOW
COVERS THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA. CONVECTIVE
PRECIPITATION...ISOLATED MODERATE TO LOCALLY STRONG IN THE
WATERS THAT ARE BETWEEN HAITI AND JAMAICA.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 84W/85W FROM 18N
SOUTHWARD...MOVING WESTWARD 20 KNOTS. THE WAVE IS CUTTING
THROUGH HONDURAS...NICARAGUA...AND COSTA RICA. NO SIGNIFICANT
DEEP CONVECTIVE PRECIPITATION IS APPARENT.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF MAURITANIA
NEAR 20N13W TO 16N20W AND 9N27W. THE ITCZ CONTINUES FROM 9N34W
TO 8N44W...INTO THE COASTAL AREAS OF FRENCH GUIANA AND
SURINAME...EVENTUALLY TO 5N55W. CONVECTIVE PRECIPITATION...
WIDELY SCATTERED TO SCATTERED MODERATE AND ISOLATED STRONG FROM
6N TO 10N BETWEEN 11W AND 18W.

...DISCUSSION...

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

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN
MEXICO NEAR 21N103W. UPPER LEVEL ANTICYCLONIC WIND FLOW CURVES
AWAY FROM MEXICO INTO THE WESTERN SECTIONS OF THE GULF OF
MEXICO. THAT NORTHWESTERLY WIND FLOW CROSSES THE SOUTHWESTERN
CORNER OF THE GULF OF MEXICO AND THE YUCATAN PENINSULA...INTO
THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...INTO THE BASE OF
A TROUGH ORIGINATES IN THE EASTERN AND SOUTHEASTERN SECTIONS OF
THE GULF OF MEXICO. THE TROUGH STARTS IN THE GULF OF MEXICO...
IT CROSSES NORTHWESTERN CUBA...AND IT REACHES ITS BASE NEAR
13N81W IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA. EARLIER
RAINSHOWERS IN CENTRAL AND SOUTHERN FLORIDA HAVE WEAKENED AND
DISSIPATED. RAINSHOWERS ARE POSSIBLE IN THE NORTHWESTERN CORNER
OF THE CARIBBEAN SEA.

A DIURNAL SURFACE TROUGH IS ALONG 23N91W 20N92W 18N92W. NO
SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS APPARENT.

A SURFACE RIDGE PASSES ACROSS THE NORTHWESTERN BAHAMAS...ACROSS
LAKE OKEECHOBEE IN FLORIDA...TO A 1019 MB HIGH PRESSURE CENTER
THAT IS NEAR 28N86W...TO THE TEXAS COAST NEAR 28N. SURFACE
ANTICYCLONIC WIND FLOW COVERS THE GULF OF MEXICO EVERYWHERE...
EXCEPT NEAR THE DIURNAL SURFACE TROUGH.

THE REST OF THE CARIBBEAN SEA...

A SURFACE TROUGH STRETCHES ACROSS THE NORTHWESTERN PART OF CUBA.
THIS TROUGH IS PART OF THE ENERGY THAT WAS ASSOCIATED WITH THE
CURRENT 84W/85W TROPICAL WAVE AS THE WAVE HAS CONTINUED TO MOVE
WESTWARD. MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW FROM A
TROUGH ALSO SPANS CUBA. CONVECTIVE PRECIPITATION...ISOLATED
MODERATE FROM 16N NORTHWARD BETWEEN 80W AND 88W.

BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW SPANS THE
CARIBBEAN SEA...EXCEPT FOR THE RIDGE AND ANTICYCLONIC WIND FLOW
THAT ARE IN THE SOUTHEASTERN CORNER OF THE AREA/ALSO IN THE
ATLANTIC OCEAN...FROM 10N TO 20N BETWEEN 54W AND 80W

TWO 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 PASSES THROUGH A 24N70W CYCLONIC CIRCULATION CENTER. THE
600 MB TO 800 MB WIND FLOW IS FROM THE SOUTHEAST ACROSS
HISPANIOLA. RAINSHOWERS ARE APPARENT IN SATELLITE IMAGERY
BETWEEN HAITI AND JAMAICA AND CUBA.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT SOUTHWESTERLY WIND
FLOW WILL MOVE ACROSS HISPANIOLA FOR THE NEXT 48 HOURS. THIS
FORECAST IS BASED ON THE IDEA THAT THE CURRENT TROUGH WILL
REMAIN TO THE WEST AND NORTHWEST JUST ENOUGH IN ORDER TO PUSH
THE SOUTHWESTERLY WIND FLOW ACROSS THE AREA. THE GFS MODEL
FORECAST FOR 500 MB SHOWS THAT MORE THAN ONE INVERTED TROUGH
WILL MOVE ACROSS HISPANIOLA DURING THE NEXT 48 HOUR PERIOD.
THE GFS MODEL FORECAST FOR 700 MB SHOWS THAT SOUTHEASTERLY-TO-
EASTERLY WIND FLOW WILL CROSS HISPANIOLA FOR THE NEXT 48 HOURS...
WITH AN ATLANTIC OCEAN-TO-GREATER ANTILLES NORTHEAST-TO-SOUTHWEST
ORIENTED RIDGE.

THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N67W...TO
A 24N70W CYCLONIC CIRCULATION CENTER...ACROSS HISPANIOLA...TO
15N75W IN THE CARIBBEAN SEA. EARLIER CONVECTIVE PRECIPITATION
THAT WAS OCCURRING INLAND IN HISPANIOLA HAS WEAKENED AND
DISSIPATED. MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW
COVERS THE ATLANTIC OCEAN FROM 20N NORTHWARD BETWEEN 54W AND
77W. RAINSHOWERS ARE POSSIBLE IN THE AREA OF CYCLONIC WIND FLOW.

A SURFACE TROUGH IS ALONG 28N48W 28N52W 25N57W. A MIDDLE LEVEL
TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 26N42W.
ISOLATED MODERATE IS FROM 25N TO 28N BETWEEN 44W AND 50W. BROKEN
TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE
ELSEWHERE FROM 24N TO 31N BETWEEN 32W AND 60W.

A SURFACE RIDGE EXTENDS FROM A 1028 MB HIGH PRESSURE CENTER THAT
IS NEAR 34N50W...THROUGH 32N59W...TO 30N66W...ACROSS THE
NORTHWESTERN BAHAMAS TO LAKE OKEECHOBEE IN FLORIDA.

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

$$
MT


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