[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 311204
TWDAT

AXNT20 KNHC 311101 AAA
TWDAT

Tropical Weather Discussion...UPDATED
NWS National Hurricane Center Miami FL
701 AM EDT WED AUG 31 2016

UPDATED FOR 31/1200 UTC POSITION FOR T.D. NINE

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
1030 UTC.

...SPECIAL FEATURES...
Hurricane Gaston is centered near 33.4N 50.2W at 31/0900 UTC or
about 740 nm east of Bermuda and about 1160 nm west of the Azores
moving northeast at 8 kt. Estimated minimum central pressure is
956 mb. Maximum sustained wind speed is 105 kt with gusts to 130
kt. Scattered to numerous moderate convection is from 32N-35N
between 48W-53W. See latest NHC Forecast/Advisory under the
AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details.

Tropical Depression Eight is centered near 34.8N 74.3W at 31/0900
UTC or about 65 nm east-southeast of Cape Hatteras North Carolina
moving northeast at 4 kt. Estimated minimum central pressure is
1011 mb. Maximum sustained wind speed is 30 kt with gusts to 40
kt. Scattered moderate convection is sheared to the northeast of
the center, from 34N-37N between 72W-74W. See latest NHC
Intermediate Public Advisory under AWIPS/WMO headers
MIATCPAT3/WTNT33 KNHC and the full Forecast/Advisory under the
AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more details.

Tropical Depression Nine is centered near 24.6N 88.1W at 31/1200
UTC or about 350 nm south-southwest of Apalachicola Florida and
about 365 nm to the west-southwest of Tampa Florida moving
northward 2 knots. Estimated minimum central pressure is 1001 mb.
Maximum sustained wind speed is 30 kt with gusts to 40 kt.
Numerous strong convection is from 22N-25N between 86W-89W.
Scattered moderate to strong convection also from 21.5N- 24N
between 83W-86W. See latest NHC Intermediate Public Advisory under
AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full
Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/WTNT24
KNHC for more details.

...TROPICAL WAVES...
A tropical wave extends across the Cabo Verde Islands from 10N26W
to 1010 mb low pressure near 15N25W to 19N24W, moving west at
15-20 kt. The gradient between the low pressure and ridging to the
north is enhancing northeast winds across the eastern Atlantic
north of 15N and east of 30W. The embedded circulation is drawing
rich deep layer moisture northward across the eastern Cabo Verde
Islands, possibly bringing a few showers to the region. The system
is also interning dry Saharan air and dust to the north and west
of the islands, limiting convection.

Another tropical wave extends from 10N40W to 19N40W moving west
at 15-20 kt. The wave coincides with mid level troughing between
35W-40W that shows up well on satellite derived high density
winds, on the leading edge of a well defined plume of deep layer
moisture. No significant deep convection is occurring with the
wave at this time. The tropical wave follows another mid level
trough centered around 50W. Model depictions indicate the
tropical wave will dampen out over the next 24 to 36 hours between
the more developed wave to the east and the troughing near 50W,
which is expected to move across the Leeward Islands through late
Thursday.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from 10N29W to 08N35N to 08N40W. The
intertropical convergence zone axis extends from 08N40W to 11N47W
to 10N553W. Convergence of southwest flow into the monsoon trough
is supporting scattered moderate convection within 60 nm of a line
from 06N30W to 10N20W. Convergent trade wind flow into the ITCZ
is supporting scattered moderate convection with 120 nm either
side of the axis between 45W and 55W.

...DISCUSSION...

GULF OF MEXICO...
Tropical Depression Nine continues to develop over the south
central Gulf this morning. Current buoy data along with a recent
scatterometer pass indicated a broad area of strong winds over
much of the eastern Gulf around T.D. Nine, but with the strongest
areas of showers and thunderstorms confined to the south central
Gulf around the center of T.D Nine and over the warmer waters of
the loop current. Scattered showers and thunderstorms persist
over the northeast Gulf as well, assisted by convergence of
persistent fresh to strong northeast to east winds. T.D. Nine is
expected to approach the Big Bend region of Florida reaching the
coast by Thursday night. It will cross portions of northern
Florida and southern Georgia and into the SW North Atlc region by
Friday.

CARIBBEAN SEA...
An upper level ridge axis extends from over T.D. Nine centered in
the south central Gulf of Mexico southeastward to the central
Caribbean. The ridging is providing an overall diffluent
environment aloft in support of scattered showers and
thunderstorms across much of the Caribbean north of 15N and west
of 80W. Training showers and thunderstorms continue to impact
portions of central and western Cuba where heavy rainfall has been
reported for the past couple of days. Scattered moderate to strong
convection is also impacting the northern portions of the Yucatan
peninsula. The subtropical ridge is building over the western
Atlantic, allowing trade wind flow to increase across the south
central Caribbean.

...HISPANIOLA...
An upper low remains in place north of Hispaniola near 23N69W.
Subsident northerly flow on the west side of the upper low has
been suppressing convection since late Monday, but scattered
showers and thunderstorms will again appear over the higher
terrain in the interior later this afternoon.

ATLANTIC OCEAN...
Aside from active tropical cyclones...scattered showers and
thunderstorms are noted over the Bahamas on the periphery of T.D. Nine
centered in the Gulf of Mexico, and elsewhere west of 70W due to
an upper low center near 23N69W, and Elsewhere the remainder of
the central and eastern Atlc is under the influence of a surface
ridge anchored by a 1027 mb high centered near 35N25W.

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

$$
CHRISTENSEN
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