[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290602
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
202 AM EDT THU SEP 29 2016

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
0545 UTC.

...SPECIAL FEATURES...

Tropical Storm Matthew at 29/0300 UTC was centered near 13.9N
63.1W or about 321 NM SSE of San Juan Puerto Rico moving west at
13 KT. Maximum sustained winds are 55 KT with gusts to 65 KT.
Estimated minimum central pressure is 1004 mb. Numerous heavy
showers are happening from 12N to 16N between 60W and 64W.
Scattered moderate convection is elsewhere from 11N to 17N between
58W and 64W. Matthew is forecast to become a hurricane by THU
night. Please refer to the NHC forecast/advisory under AWIPS/WMO
headers WTNT24 KNHC/TCMAT4, or visit the NHC website at
http://hurricanes.gov for additional details.

...TROPICAL WAVES...

A tropical wave is in the Central Atlc extending from 06N to 16N
with axis near 31W moving W at 15 kt over the past 24 hours. This
is a low amplitude wave in a region of unfavorable deep layer
wind shear. CIRA LPW imagery and Meteosat enhanced imagery show
dry air in the wave environment that along dust support lack of
convection at the time.

A tropical wave is in the Central Atlc extending from 05N to 15N
with axis near 44W expected to move at 15 kt over the next 24
hours. Unfavorable deep layer wind shear is in the northern wave
environment supporting lack of convection N of 12N. CIRA LPW
imagery show a moderate moist environment elsewhere with pockets
of dry air mainly W the wave axis where isolated showers are
observed. Scattered moderate to isolated strong showers are from
09N to 12N between 33W and 44W.

A tropical wave is in the W Caribbean extending from 09N to 18N
with axis near 83W moving W at 10 to 15 KT over the past 24 hours.
The wave is in a region of abundant low level moisture and
favorable deep layer wind shear that support scattered heavy
showers and tstms from 15N to 21N between 81W and 87W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends over Africa reaching the east Atlantic
near 17N16W through 11N20W to 08N29W. Aside from the convection
associated with the tropical wave near 44W, scattered heavy
showers and isolated tstms possibly associated with another
tropical wave are from 05N to 16N E of 28W.

...DISCUSSION...

GULF OF MEXICO...

Weak low pressure dominates across the Gulf due to the passage of
an already dissipated cold front in the NE basin and the presence
of a surface trough off the E coast of Mexico extending from
25N96W to 18N95W. These features are providing the basin with
gentle variable wind flow. Aloft, a broad anticyclone covers the
western portion of the basin while an upper trough extends over
the eastern waters and Florida. Diffluent flow between these two
upper level features along with low level moisture in the
southern basin support scattered to isolated showers over the SE
Gulf while the surface trough generates heavy showers and tstms
from 20N to 23N W of 96W. A reinforcing cold front will move
across the Gulf waters Thu becoming stationary from N Florida to
the central basin to Tampico Mexico on Friday and dissipating
Saturday.

CARIBBEAN SEA...

The main feature of concern in the Caribbean is T.S. Matthew
located over the far E basin. Numerous heavy showers associated
with it are happening from 12N to 16N between 60W and 64W.
Scattered moderate convection is elsewhere from 11N to 17N between
58W and 64W. See special features for further details. Over the
NW basin, a tropical wave with axis near 84W generate scattered
showers from 15N to 21N between 81W and 87W. See the tropical
waves section for more details. Strong dry air subsidence and
unfavorable deep layer wind shear support fair weather elsewhere.
Fresh to strong winds are from 11N to 13.5N between 70W and 76W.
Gentle to moderate trades are elsewhere, except in the vicinity of
T.S. Matthew. Matthew is forecast to become a hurricane by THU
night.

...HISPANIOLA...

Currently fair weather conditions are across the Island. However,
T.S. Matthew is forecast to pass south of Hispaniola as a
hurricane by Friday. Cloudiness associated with Matthew is
expected to spread over the island early THU with an increase in
showers and thunderstorms late THU into FRI. The large envelope of
Matthew may result in the potential for locally heavy rains over
Hispaniola. This will greatly depend on the ultimate track of
Matthew. For additional information on Matthew please refer to the
special features section above.

ATLANTIC OCEAN...

A broad middle-level trough extends across the SE CONUS and covers
Atlc waters W of 72W, supporting scattered showers and tstms in
that area N of 24N. The remainder basin is being dominated by a
broad surface ridge anchored by a 1037 mb high in the north central
Atlc.

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

$$
RAMOS
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