[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 311756
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
156 PM EDT Wed Oct 31 2018

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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...

Hurricane Oscar is centered near 36.6N 51.6W at 31/1500 UTC or
610 nm S of Cape Race Newfoundland moving NE at 25 kt. Estimated
minimum central pressure is 979 mb. Maximum sustained wind speed
is 65 kt with gusts to 80 kt. Numerous moderate convection extends
in the northern semicircle out to 210 nm from the center. A
faster motion toward the northeast or north-northeast over the
north Atlantic Ocean is expected during the next couple of days.
Oscar is expected to become an extratropical low over the north-
central Atlantic Ocean later today. Oscar will remain a powerful
post-tropical cyclone over the north-central and northeastern
Atlantic Ocean into the weekend. See the latest NHC
forecast/advisory under AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC
for more details.

...Strong Gulf of Mexico Cold Front...

A cold front will move off the Texas coast into the NW Gulf of
Mexico by early Thursday and continue moving southeast through the
basin. A pre-frontal squall line with strong thunderstorms is
likely within 180 nm ahead of the front over the northern Gulf,
mainly north of 27N. The squall line should enter the NW Gulf from
the Texas coast by late tonight and travel quickly eastward
through the northern Gulf into Thursday evening. Brief gale force
winds are possible in the squalls, with seas ranging between 6-9
ft. Refer to the Offshore Waters Forecast under AWIPS/WMO headers
OFFNT4/FZNT4 KNHC for more details.

...TROPICAL WAVES...

A tropical wave extends its axis along 47/48W from 01N to 12N,
moving west at 10-15 kt. Model guidance shows a 700 mb trough
to the east of the wave. TPW imagery depicts moderate to high
moisture content near and east of the wave axis. Scattered
moderate convection extends 90 nm on either side of the wave
from 05N to 08N.

A tropical wave extends its axis along 19W from 01N to 12N. This
wave is noted in model guidance at 700 mb and TPW imagery show
high moisture content associated with this wave. Scattered
moderate convection extends south of 12N between 14W to 23W.

Tropical wave that was along 59W has dissipated and has been
removed from the analysis.

...MONSOON TROUGH/ITCZ...

The monsoon trough is analyzed from 12N16W to 05N25W. The ITCZ
extends from 05N26W to 07N45W, then resumes 07N50W to 06N57W.
Aside from the convection related to the two tropical waves,
isolated moderate convection is within 150 nm on either side of
the ITCZ between 26W-38W.

GULF OF MEXICO...

A 1024 mb high pressure centered over the coast of North Carolina
extends a ridge across the eastern and central Gulf of Mexico.
Scattered showers and thunderstorms are observed over the
northwest Gulf of Mexico north of 28N and west of 92W, extending
along the Texas and western Louisiana coast. This activity will
increase into late this afternoon as a squall line develops ahead
of the cold front mentioned above in the Special Features
section. A weak trough is noted over the Bay of Campeche near
20N93W. No significant convection is seen with this trough.

Winds and seas will begin to increase across the Gulf tonight as
return flow sets up across the western half of the Gulf ahead of
a strong cold front expected to move off the Texas coast by early
Thu with strong S to SW wind flow ahead of it, and gale-force
wind gusts. The front will reach from the mouth of the Mississippi
River to near Veracruz, Mexico Thu evening, from near Tampa Bay
to the central Yucatan Peninsula Fri evening, then stall across
the Straits of Florida to Cancun, Mexico Sat morning before
drifting NW through Sun. For more information in regards to this
feature, see the Special Features section above.

CARIBBEAN SEA...

A stationary front extends from the west Atlantic to eastern
Cuba. Scattered showers are noted in the vicinity of Jamaica,
Hispaniola and along the Windward Passage. In the far southwest
Caribbean, scattered moderate to isolated strong convection is
south of 11N near NW Colombia and the coast of Panama due to the
monsoon trough proximity. Strengthening high pressure over the
western Atlantic through Thu afternoon will act to freshen the
tradewinds across the central Caribbean. The high will then
continue to shift ENE through the weekend to produce fresh to
strong tradewinds across the Caribbean east of 80W, especially the
south-central Caribbean. These winds will be strongest at night
close to the coast of Colombia. A Gulf of Mexico cold front will
move SE to the Yucatan Channel and far NW Caribbean Sat morning
and stall, then drift NW and back into the Gulf late Sat and Sun.

ATLANTIC OCEAN...

A cold front enters the area near 32N54W extends to 28N60W to 23N79W.
To the east, a second cold front extends from 30N52W to 25N60W to 22N68W,
then becomes stationary to eastern Cuba. These fronts are located
southwest of Hurricane Oscar. A surface trough extends from
28N50W to 21N64W. Scattered showers are observed from the north
coast of Dominican Republic to 23N and between 62W-71W. Scattered
moderate convection is also present from 24N-31N between 44W and
53W. Large north swell will affect the waters north of 28N east
of 25W through early Thursday.

The two frontal boundaries from the central Atlc to the southern
Bahamas will become aligned E to W and merge along 20N-21N by Fri
evening as strong high pressure to the N shifts eastward along
33N. Moderate swell associated with exiting Oscar over the central
Atlc will affect waters E of the Bahamas through Thu. Another
cold front will move offshore of N Florida early Sat with strong
southerly flow ahead of it Fri. The front is expected to weaken
and stall from near 31N73W to the Florida Keys Sat evening before
shifting NW Sat night through Sun.

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

$$
MTorres/ABH
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