AXNT20 KNHC 301049
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
649 AM EDT TUE AUG 30 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 0600 UTC surface analysis and satellite imagery
through 1030 UTC.
Hurricane Gaston is centered near 32.0N 54.0W at 30/0900 UTC or
about 550 nm east of Bermuda and about 1370 nm west of the Azores
moving northeast at 5 kt. Estimated minimum central pressure is
971 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt.
Scattered to numerous moderate convection is from 29N-34N between
51W-56W. See latest NHC Forecast/Advisory under the AWIPS/WMO
headers MIATCMAT2/WTNT22 KNHC for more details.
Tropical Depression Eight is centered near 33.9N 75.0W at 30/0900
UTC or about 80 nm southeast of Cape Hatteras North Carolina
moving northwest at 5 kt. Estimated minimum central pressure is
1010 mb. Maximum sustained wind speed is 30 kt with gusts to 40
kt. Scattered moderate convection is observed from 32N-35N between
72W and 75W. 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 23.8N 86.6W at 30/0900
UTC or about 270 nm west of Key West Florida and about 235 nm
west-northwest of Havana Cuba moving west at 6 kt. Estimated
minimum central pressure is 1003 mb. Maximum sustained wind speed
is 30 kt with gusts to 40 kt. Numerous strong convection is
observed from 21N-26N between 84W-87W. See latest NHC
Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/WTNT24
KNHC for more details.
A tropical wave is analyzed from 09N35W to 18N35W moving west at
15 to 20 kt. The tropical wave is well represented on animated
precipitable water imagery and GOES high density winds for the
lower and mid levels of the atmosphere. Aside from mid level
cloudiness, no significant sensible weather is associated with
this tropical wave and minimal amplification at the surface.
Global models indicate the tropical wave will continue west
although remain fairly weak at the surface, possible bringing a
few showers into the Leeward and Windward Islands by Thursday.
A tropical wave emerging off the African coast reaches from
08N19W to 1008 mb low pressure near 16N20W to 18N19W. The
gradient bewteen the tropical wave and high pressure to the north
is enhancing northeast flow across the Canary Islands. Scattered
moderate showers and thunderstorms are evident off the coast of
Senegal, Gambia and Guinea-Bissau. The tropical wave is expected
to stay intact as it tracks westward across the Atlantic over the
next several days, accompanied by areas of fresh to strong winds and
scattered showers and thunderstorms.
The monsoon trough extends from 09N21W to 08N27W to 09N40W. The
intertropical convergence zone axis extends from 09N40W to
06N57W. Scattered moderate convection is evident within 120 nm
south of the monsoon trough and ITCZ axes between 25W and 45W, and
within 180 nm north of the ITCZ between 25N and 55W.
GULF OF MEXICO...
The primary concern is Tropical Depression Nine centered in the
southeast Gulf under an upper level anticyclonic circulation
allowing slow and gradual strengthening during the next several
days. A weak trough remains in place over the northwest Gulf
reaching from a 1010 mb low pressure system centered near 27N97W
to 27N92W. Moderate to fresh northeast to east winds are noted
north of the trough axis and west of 90W. Convergence of these
winds is supporting scattered showers and thunderstorms in the
same vicinity. Light to gentle breezes are noted elsewhere.
Looking ahead, T.D. Nine is expected across central portions of
the basin and will begin re- curving to the northeast and in the
general direction of the Florida Big Bend region, reaching the
Florida coast Thursday afternoon.
Divergent flow aloft between an upper anticyclone over T.D. Nine
in the southeast Gulf and an upper low east of the Bahamas is
supporting scattered showers and thunderstorms over the north
central Caribbean this morning, north of 20N to the coast of Cuba
as well as the Yucatan Channel. Scattered showers and
thunderstorms are training over the western portion of Cuba into
T.D. Nine to the north. The normally dominant subtropical ridge
north of the area is temporarily weakened due to the presence of
T.D. Nine and a persistent trough north of Hispaniola, resulting
in only moderate to fresh trade wind flow across the southwest
Caribbean this morning. Yesterday's sounding data from Trinidad
indicated a low latitude trough moved into the far southeast
Caribbean early Saturday. Scttered showers and thunderstorms along
with slightly stronger trade wind flow are noted across the
southeast Caribbean currently. Trade winds will increase across
much of the south- central Caribbean through mid week as high
pressure builds north of area.
Scattered showers and thunderstorms will develop today over the
mountainous interior portions of Hispaniola, due in part to
daytime heating but also due to divergence aloft between an upper
anticyclone over the southeast Gulf and an upper low to the
northeast of the region. The pattern will be similar through mid
Aside from active tropical cyclones, scattered showers and
thunderstorms are noted across the Bahamas and adjacent waters
including north of the Bahamas associated with an upper low
centered over the coast of Georgia. Another upper low centered
near 24N68W, supporting scattered moderate convection from 23N to
26N between 65W and 70W. Elsewhere, the remainder of the central
and eastern Atlc is under the influence of a surface ridge
anchored by a 1022 mb high centered near 31N42W. A surface trough
is evident into the ridge from 18N46W to 23N45W to 26N42W.
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