Tropical Weather Discussion
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000
AXNT20 KNHC 060604
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
104 AM EST Wed Dec 6 2017

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 IN THE GULF OF MEXICO...

.GULF OF MEXICO COLD FRONT FROM 30N88W TO 26N97W. NW OF FRONT NE
WINDS 25 TO 35 KT. SEAS BUILDING TO 8 FT. SCATTERED TSTMS WITHIN
90 NM OF FRONT.
.18 HOUR FORECAST COLD FRONT FROM 30N85W TO NEW LOW PRES 26N95W
1012 MB WITH COLD FRONT S TO 21N97W. N OF 27N NW OF FRONT NE
WINDS 20 TO 30 KT. SEAS TO 10 FT. S OF 27N W OF FRONT NW TO N
WINDS 20 TO 25 KT. SEAS TO 8 FT. SCATTERED TSTMS WITHIN 120 NM
OF FRONT.
.24 HOUR FORECAST COLD FRONT FROM 29N83W TO LOW PRES 26N93W 1012
MB WITH COLD FRONT S TO 20N96W. W OF LINE FROM 30N83W TO 25N96W
NE WINDS 20 TO 30 KT. SEAS TO 11 FT. FROM 21N TO 25N W OF 95W NW
TO N WINDS 20 TO 30 KT. SEAS TO 9 FT. SCATTERED TSTMS WITHIN 120
NM OF FRONT.
.42 HOUR FORECAST COLD FRONT FROM 27N83W TO LOW PRES 26N89W 1011
MB WITH COLD FRONT SW TO 23N94W TO 18N93W. W OF LINE FROM 29N85W
TO 24N93W N TO NE WINDS 20 TO 30 KT. SEAS 8 TO 13 FT. FROM 21N
TO 24N W OF 96W NW TO N WINDS 25 TO 35 KT. SEAS 9 TO 13 FT.
ELSEWHERE W OF LINE FROM 24N93W 18N95W NW TO N WINDS 20 TO 25
KT. SEAS TO 10 FT. SCATTERED TSTMS WITHIN 120 NM OF FRONT.
.48 HOUR FORECAST COLD FRONT FROM 27N83W TO LOW PRES 26N87W 1011
MB WITH COLD FRONT SW TO 23N92W TO 18N93W. FROM 21N TO 24N W OF
95W NW TO N WINDS 30 TO 35 KT. SEAS 10 TO 15 FT. ELSEWHERE W OF
LINE FROM 30N84W TO 22N93W TO 18N94W N TO NE WINDS 20 TO 30 KT.
SEAS 8 TO 14 FT. SCATTERED TSTMS WITHIN 120 NM OF FRONT.


...ITCZ/MONSOON TROUGH...
The monsoon trough passes through the coastal sections of Guinea-
Bissau near 12N16W to 08N18W. The ITCZ continues from 08N18W to
06N30W, 05N44W, and to 02N50W at the coast of Brazil. Precipitation:
isolated to widely scattered moderate and locally strong
rainshowers are from 01N to 09N between 10W and 60W.

...DISCUSSION...

THE GULF OF MEXICO...

Middle level-to-upper level westerly wind flow and comparatively-
drier air in subsidence cover the Gulf of Mexico to the east of
the line from 30N86W to 27N90W to 23N95W to 19N94W. A middle level
to upper level trough extends from the SE Gulf of Mexico into the
Yucatan Channel.

A cold front passes through the Florida Panhandle, through SE
Louisiana, to the lower Texas Gulf coast. Upper level westerly
wind flow is to the west of the cold front. Low level clouds and
rain are along the frontal boundary.

A surface ridge passes through central Florida, into the central
Gulf of Mexico, and finally into the SW corner of the Gulf of
Mexico.

...CURRENT CONDITIONS AND WEATHER, FOR THE OFFSHORE OIL PLATFORM
SITES, THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N
NORTHWARD AND FROM 88W WESTWARD...

LIFR: none.
IFR: KMZG, KBBF, KEMK, KHQI, KEHC, KVQT, KEIR, and KSPR.
MVFR: KBQX, KXIH, KVAF, KVOA, and KDLP.

CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE
U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

from the DEEP SOUTH of TEXAS to TALLAHASSEE in FLORIDA: IFR/MVFR
and isolated areas of LIFR, and rain, some thunder, with the
current cold front. for the rest of FLORIDA: MVFR or VFR. the cold
front has not reached Florida, yet.

THE CARIBBEAN SEA...

Large scale upper level anticyclonic wind flow moves through the
SW corner of the area, toward Hispaniola, and then curving toward
the east and southeast.

Middle level-to-700 mb NE wind flow covers the area that is from
16N northward from 80W westward.

A surface trough extends from central Panama to NE Nicaragua and E
Honduras. The monsoon trough is along 10N75W in Colombia, to
09N80W in Panama, beyond 10N86W in the eastern Pacific Ocean.
Precipitation: scattered to numerous strong from 10N to 13N
between 80W and 83W. isolated moderate to locally strong elsewhere
from 17N southward between 80W and the coastline of Central
America, and from the coast to 10N between 77W and 79W along the
coast of Panama.

A surface trough is in the E part of the Caribbean Sea, along
18N65W 15N66W 10N67W. Precipitation: isolated moderate rainshowers
are from 10N to 17N between 60W and 70W.

24-hour rainfall totals in inches, for the period that ended at
06/0000 UTC, according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.16 in
Curacao, and 0.07 in Guadeloupe.

...HISPANIOLA...

Upper level NW wind flow is approaching the area from the
northwest, from the waters that are between the Bahamas and Cuba.
Upper level SW wind flow is approaching the area from the SW
corner of the Caribbean Sea.

SURFACE OBSERVATIONS...VFR for Port-au-Prince in Haiti. in the
DOMINICAN REPUBLIC: Puerto Plata: rainshowers with thunder.
VFR, elsewhere. few cumulonimbus clouds in Barahona and in Santo
Domingo.

The GFS MODEL forecast for 250 mb shows that a ridge will start
along the line from Colombia to the Yucatan Peninsula, to a line
from Colombia through the Windward Passage. The GFS MODEL
forecast for 500 mb shows that anticyclonic circulation center
will be just to the east of the Bahamas along 23N, at the start of
the 48-hour forecast period. The anticyclonic circulation center
eventually will move eastward, more into the Atlantic Ocean, by
about 550 nm at the end of the 48-hour forecast period. NW wind
flow will be moving across Hispaniola at the start of day one, and
the wind flow eventually will become cyclonic with an east-to-
west oriented trough by the end of day one. Day two will start
with the trough being pushed southward by the Atlantic Ocean ridge
and the large-scale anticyclonic circulation center. Expect SE-
to-S wind flow during day two. The GFS MODEL forecast for 700 mb
shows that day one will start with a NW-to-SE oriented ridge,
which will give way to NE wind flow, and then followed by a NW-
to- SE oriented inverted trough across the area at the end of day
one. Day two will consist of first E-to-SE wind flow across the
area, giving way to large-scale SE wind flow as part of the large-
scale Atlantic Ocean anticyclonic wind flow.

THE ATLANTIC OCEAN...

A deep layer trough is moving through the central sections of the
Atlantic Ocean. The trough supports a cold front that passes
through 32N42W to 27N47W to 25N56W. A surface trough remains from
an already-dissipated stationary front from the last 24 hours or
so, along 30N41W 21N48W 21N59W. Precipitation: rainshowers are
within 120 nm on either side of the line that passes through
32N38W 24N41W 20N45W.


For additional information please visit
http://www.hurricanes.gov/marine

$$
MT



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