[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041204
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
804 AM EDT Thu Oct 4 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 0600 UTC surface analysis and satellite imagery through
1115 UTC.

...SPECIAL FEATURES...

Hurricane Leslie is centered near 31.4N 57.1W at 04/0900 UTC or
400 nm E of Bermuda moving N at 7 kt. Estimated minimum central
pressure is 976 mb. Maximum sustained wind speed is 70 kt with
gusts to 85 kt. Scattered moderate convection extends outward to
270 nm north and northwest of the center. Elsewhere scattered
moderate convection is within 180 nm of the center. A northward
motion with an increase in forward speed is expected through
tonight. A reduction in speed is forecast on Friday and Friday
night, with Leslie accelerating toward the east or east-southeast
over the weekend. Gradual weakening is forecast during the next
several days. See the latest NHC forecast/advisory under AWIPS/WMO
headers MIATCPAT3/WTNT33 KNHC for more details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave extends its axis along 27W
from 02N-14N, moving westward around 15-20 kt. Scattered moderate
convection is from 04N-07N between 30W-33W, with another area of
scattered moderate convection from 06N-09N between 21W-24W. Total
Precipitable Water imagery shows deep moisture surrounding the
wave. The wave has an associated 700 mb trough, as shown by model
analyses.

A central Atlantic tropical wave is along 46W from 05N-15N moving
westward around 20 kt. Scattered showers are occurring along and
in the vicinity of the wave's axis between 40W-48W. The wave has
an associated 700 mb trough, as shown by model analyses.

An eastern Caribbean tropical wave has its axis along 66/67W from
08N-19N, moving westward at 10 kt. The wave is not producing any
significant convection due to an area of mid-level ridging and
sinking air that prevails across the eastern Caribbean.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Guinea-Bissau near
11N15W to 10N25W. The ITCZ extends from 04N29W to 08N44W, then
continues west of a tropical wave from 07N48W to the coast of
northeast Venezuela near 09N61W. Aside from the convection
mentioned in the tropical waves section above, scattered showers
and thunderstorms are observed well north of the ITCZ from 12N-16N
between 33W-37W.

...DISCUSSION...

GULF OF MEXICO...

A surface trough continues over the north-central Gulf waters
along 90W between 25N-29N. Shower activity has diminished with
this feature, and there are now only isolated showers occurring
along and east of the trough axis. Enhanced moisture associated
with this trough is seen on GOES-16 TPW imagery. Isolated showers
are noted over the Bay of Campeche and adjacent land areas near
Veracruz. Weak surface ridging prevails across the remainder of
the basin with little shower activity.

Expect ridging to prevail over the forecast area during the next
few days. A surface trough will develop each evening over the
Yucatan Peninsula. The trough will move into the SW Gulf
overnight, where it will dissipate each morning. Moderate to fresh
winds will accompany the trough.

CARIBBEAN SEA...

A tropical wave is over the eastern Caribbean. Refer to the
Tropical Waves section above for details. A broad surface trough
is over the western Caribbean, analyzed from 20N78W to a 1008 mb
low near 15N81W to 12N82W. This trough and low are part of a
large cyclonic gyre, defined by a broad area of low pressure,
which covers portions of Central America and the western
Caribbean. Satellite imagery shows numerous moderate and scattered
strong convection just east of the trough axis from 12N-17N
between 76W- 81W. Scattered showers and storms are noted elsewhere
from 11N-18N between 74W-84W. Some slow development of this
system is possible this weekend or early next week as the system
drifts northwestward. A mid to upper level trough extending over
the Bahamas and Greater Antilles will help advect moisture
northwestward as the week progresses. As a result, heavy rainfall
is likely to spread over portions of Hispaniola, Jamaica, Cuba,
the Yucatan Peninsula and Central America this weekend into early
next week.

Large NNE swell generated from Hurricane Leslie will continue to
pass through the Atlantic passages into the Caribbean through the
end of the week before subsiding.

ATLANTIC OCEAN...

Two tropical waves over the tropical Atlantic between the west
coast of Africa and the Lesser Antilles are described in the
Tropical Waves section above. Hurricane Leslie is described in
the Special Features section above.

A weak surface trough located between the NW Bahamas and South
Florida is causing scattered showers and thunderstorms over the
NW Bahamas. This activity should continue today as it moves
westward. The trough is likely to enhance showers and
thunderstorms over South Florida today. Another surface trough is
located south of Hurricane Leslie from 26N60W to 21N68W. No
significant convection is noted near the trough at this time. An
E-W surface trough is analyzed to the east of Hurricane Leslie
from 29N43W to 31N33W. Scattered showers and isolated
thunderstorms are seen south of this trough from 26N-30N between
30W-40W.

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

$$
ERA/Hagen
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