[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041727
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
127 PM 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...SPECIAL FEATURES...

Hurricane Leslie is centered near 32.5N 57.2W at 04/1500 UTC or
390 nm E of Bermuda moving N at 8 kt. Estimated minimum central
pressure is 979 mb. Maximum sustained wind speed is 65 kt with
gusts to 80 kt. Scattered moderate convection extends outward to
270 nm in the northwest quadrant and 210 nm in the other quadrants.
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 turning toward the east or east-southeast
over the weekend. Gradual weakening is forecast during the next
several days, and Leslie may weaken to a tropical storm on
Friday. 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 28W
from 03N-15N, moving westward at 10-15 kt. Scattered moderate
convection is noted within 270 nm of the wave axis from 04N-13N.
GOES-16 Total Precipitable Water imagery shows a moisture maximum
surrounding the wave. The wave has an associated 700 mb trough, as
depicted by model analyses.

A central Atlantic tropical wave is along 47W from 06N-15N moving
westward around 15 kt. Scattered showers and isolated
thunderstorms are occurring along the wave axis and extending to
180 nm east of the wave axis from 08N-15N. 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
09N-19N, moving westward around 10 kt. Isolated showers and
thunderstorms are near the wave axis north of 16N.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Guinea-Bissau near
11N15W to 10N20W to 07N33W. The ITCZ extends from 07N33W to
08N45W, then continues west of a tropical wave from 08N48W to the
coast of northeast Venezuela near 09N61W. Aside from the
convection mentioned in the tropical waves section above, isolated
showers and thunderstorms are noted along and within 120 nm north
of the ITCZ between 51W-56W. Scattered moderate and isolated
strong convection is occurring along the west coast of Africa over
Guinea-Bissau and western Guinea. This scattered activity extends
offshore the west coast of Africa for 120 nm from 06N-12N.

...DISCUSSION...

GULF OF MEXICO...

Scattered showers and isolated thunderstorms are moving westward
over the northern Gulf from 25N-30N between 87W-92W. This activity
is being enhanced by an area of upper-level diffluence over the
Gulf stemming from an upper-level ridge over the south-central
U.S. GOES-16 TPW imagery shows that the highest moisture in the
area is near 90W-92W moving westward. These showers and storms
should diminish before reaching 94W as they encounter increasingly
pronounced low and mid level ridging. A surface trough is
analyzed over the central Bay of Campeche. Scattered showers and
isolated thunderstorms are noted west of the trough, just offshore
the coast of Mexico between Veracruz and Tampico.

Expect ridging to prevail over the forecast area through the
weekend. 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 large cyclonic gyre, defined by a broad area of low pressure,
covers a portion of Central America and the western Caribbean Sea.
Within this gyre, a surface trough is analyzed from 20N80W to a
1007 mb low near 16N83W to 11N83W. Satellite imagery shows
scattered moderate to isolated strong convection from 11N-16N
between 75W-82W. Scattered showers and thunderstorms are noted
elsewhere from 11N-18N between 70W-85W. Some slow development of
this system is possible this weekend or early next week as the
system drifts northwestward across the northwestern Caribbean Sea
and the southern Gulf of Mexico. A mid to upper level trough
extending over the Bahamas and Greater Antilles will help advect
moisture northwestward over the next several days. As a result,
heavy rainfall is likely to spread over portions of Hispaniola,
Jamaica, Cuba, the Yucatan Peninsula and Central America Friday
through early next week.

A tropical wave is over the eastern Caribbean. Refer to the
Tropical Waves section above for details. 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 are over the tropical Atlantic between the
west coast of Africa and the Lesser Antilles. See above.
Hurricane Leslie is described in the Special Features section
above.

A weak surface trough located near the east coast of South
Florida is enhancing coverage of showers and thunderstorms over
the NW Bahamas and the southern and central Florida peninsula.
This activity should continue through this afternoon as the trough
moves westward. Another surface trough is analyzed from 21N65W to
26N60W. Scattered showers are noted near the southern end of this
trough from 20N-22N between 60W-70W. A SW-NE band of scattered
moderate convection about 90 nm wide extends from 22N58W to
29N50W. GOES-16 TPW imagery indicates that deep tropical moisture
from the Caribbean is being drawn northeastward across the
Atlantic due to the mid-upper level steering flow between Leslie
and the ridge well to the southeast of Leslie. An E-W surface
trough is analyzed to the east of Hurricane Leslie from 31N47W to
29N40W to 31N32W. Scattered showers and thunderstorms are seen
south of this trough from 25N-28N between 32W-41W. Another area
of showers is noted within 90 nm of a line from 14N43W to 19N35W.
Enhanced moisture from the tropical wave along 47W is streaming
northeastward between an upper-level trough to the northwest and
an upper-level ridge to the southeast.

A high pressure ridge off the southeast coast of the U.S. is
leading to generally quiet weather in the area between Bermuda and
the Bahamas.

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

$$
Hagen
This weather bulletin was brought to you by:
www.nashvilleweather.net