[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 031205
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 AM EDT Wed Oct 3 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...

Leslie has strengthened to a hurricane as of 03/0900 UTC.
Hurricane Leslie is centered near 29.6N 56.9W or 440 nm ESE of
Bermuda. Movement is stationary. Estimated minimum central
pressure is 980 mb. Maximum sustained wind speed is 65 kt with
gusts to 80 kt. Scattered moderate convection is within 180 nm of
the center in the NE quadrant and within 90 nm in the other three
quadrants. Little motion is expected today. A northward motion is
forecast to begin tonight, and this motion should continue
through Friday night. Some additional strengthening is forecast
during the next day or so. 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 20W
from 02N-15N, moving westward 15 kt. Scattered moderate
convection is occurring within 150 nm east and within 60 nm west
of the wave's axis from 04N-12N. Total Precipitable Water imagery
shows deep moisture surrounding the wave. The wave has an
associated 700 mb trough, as shown by model analyses.

A tropical wave has been added to the analysis along 39W from
5N-14N. Movement is estimated to be westward around 15 kt.
Scattered showers and thunderstorms are occurring where the wave
intersects the monsoon trough from 08N-11N between 36W-44W. The
wave has an associated 700 mb trough, as shown by model analyses.

An eastern Caribbean tropical wave has its axis along 62/63W from
06N-18N, moving westward at 10-15 kt. A well-defined 700 mb
trough is shown in model analyses just east of where the wave is
analyzed, but lacks significant convection. In fact, little to no
shower activity has been observed with this wave during the past
24 hours as it passed through the Lesser Antilles. A TPW
animation shows a slight moisture maximum associated with the wave
compared to the surrounding area, but this maximum is not as
pronounced as it was yesterday.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of west Africa near the
Senegal/Mauritania border near 16N16W to 08N21W to 08N31W to
09N44W. The ITCZ extends from 09N44W to 08N59W. Aside from the
convection mentioned in the tropical waves section above,
scattered showers are observed within 120 nm north and 60 nm south
of the ITCZ between 44W-47W.

...DISCUSSION...

GULF OF MEXICO...

A surface trough is analyzed over the northeastern Gulf from near
Tallahassee to near 26N85W. Scattered showers and isolated
thunderstorms are occurring within 60 nm of the trough axis.
This trough, along with increasing moisture in the northeastern
Gulf, will continue enhancing convection over the northeastern and
north-central Gulf today. Another trough extends across the Bay
of Campeche from 23N96W to 19N94W with scattered showers. Surface
ridging prevails across the remainder of the basin, especially
over the northwest Gulf, where little to no shower activity is
noted.

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
section above for details. A broad surface trough was analyzed
along 82W at 06Z. Although subsequent satellite-derived wind data
confirms broad turning in the southwest Caribbean west of 80W, the
trough axis farther north is closer to 79W, suggesting that the
surface trough is tilted. Regardless, this trough is associated
with a broad area of low pressure located over the southwestern
Caribbean Sea. Satellite imagery shows numerous moderate and
scattered strong convection from the north coast of western
Venezuela to 15N between 69W-74W. This convection is enhanced by
an area of upper-level diffluence. Isolated showers and
thunderstorms are elsewhere over the southwest Caribbean Sea. Some
slow development of this system is possible this weekend while
the low drifts across the northwestern Caribbean Sea. A deepening
mid to upper level trough over the northern Caribbean and Greater
Antilles will help advect moisture northward as the week
progresses. As a result, heavy rain is likely to spread over
sections of Hispaniola and Jamaica later this week and into the
weekend.

Large NNE swell generated from Leslie will continue to move
through the Atlantic passages into the Caribbean.

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 broad mid to upper-level trough over Leslie combined with an
area of upper-level diffluence to the southeast of the system
continues to enhance convection from 25N-31N between 37W-45W.
Scattered showers and thunderstorms are also seen from 21N-26N
between 50W-56W. The eastern portion of the forecast area is
under the influence of a surface ridge, anchored by a 1018 mb
surface high near 27N28W.

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

$$
ERA/Hagen
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