AXNT20 KNHC 301803
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
203 PM 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 1200 UTC surface analysis and satellite imagery through
Hurricane Gaston is centered near 32.2N 52.9W at 30/1500 UTC or
about 604 nm east of Bermuda and about 1312 nm west of the Azores
moving east-northeast at 7 kt. Estimated minimum central pressure
is 968 mb. Maximum sustained wind speed is 90 kt with gusts to
110 kt. Numerous heavy showers are from 30N to 34N between 50W
and 55W. See latest NHC Forecast/Advisory under the AWIPS/WMO
headers MIATCMAT2/WTNT22 KNHC for more details.
Tropical Depression Eight is centered near 34.2N 75.3W at 30/1500
UTC or about 61 nm south of Cape Hatteras North Carolina moving
north-northwest at 4 kt. Estimated minimum central pressure is
1011 mb. Maximum sustained wind speed is 30 kt with gusts to 40
kt. Scattered showers are observed from 32N to 35N between 70W
and 81W. 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 24.0N 87.2W at 30/1500
UTC or about 295 nm west of Key West Florida and about 269 nm
west of Havana Cuba moving west at 6 kt. Estimated minimum
central pressure is 1004 mb. Maximum sustained wind speed is 30
kt with gusts to 40 kt. Numerous heavy showers and scattered tstms
are observed from 21N to 25N between 85W and 90W. Scattered heavy
showers and isolated tstms are from 20N to 24N between 79W and 85W.
See latest NHC Forecast/Advisory under the AWIPS/WMO headers
MIATCMAT4/WTNT24 KNHC for more details.
A tropical wave is over the eastern Atlantic extending from 08N to
19N with axis near 21W expected to move at 15 kt within the next
24 hours. The wave is associated with a 1010 mb low that is
centered east of the Cabo Verde Islands near 16N20W. Enhanced
Meteosat imagery show Saharan dry air and dust intrusion into the
wave environment, which is limiting the convection to scattered
showers mainly east of the wave axis.
A tropical wave is in the central Atlantic extending from 09N to
20N with axis near 36W expected to move at 15 kt within the next
24 hours. Enhanced Meteosat imagery show abundant Saharan dry air
and dust in the wave environment, which is hindering convection
at the time.
The monsoon trough extends from 08N22W to 07N34W to 07N42W. The
intertropical convergence zone axis extends from 07N42W to
08N50W to the coast of Venezuela near 08N60W. Scattered moderate
convection is evident within 120 nm south of the monsoon trough
and ITCZ axis between 43W and 51W, and within 180 nm north of the
ITCZ between 42W and 60W.
GULF OF MEXICO...
The primary concern in the basin continues to be Tropical
Depression Nine centered in the southeast Gulf under an upper
level anticyclonic circulation allowing slow and gradual
strengthening during the next several days. See special features
section for more details. A weak surface trough remains in place
over the northwest Gulf extending from 28N92W to 28N95W to 26N97W.
Upper diffluence aloft over this feature support numerous heavy
showers and scattered tstms N of 25N W of 94W and scattered
showers elsewhere W of 92W. Scatterometer data show fresh to
strong northeast to east winds north of 26N. Light to gentle
breezes are noted elsewhere in the SW basin. Looking ahead, T.D.
Nine is expected to intensify into a tropical storm tonight and
reach the Florida Big Bend 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 heavy showers and thunderstorms over the NW
Caribbean N of 18N W of 78W, including western and central Cuba.
This convection also extends to the Yucatan Channel and as
isolated showers over Hispaniola and Windward Passage. A surface
trough is south of Puerto Rico extending from 11N67W to 17N66W.
The trough is associated with shallow moisture as indicated by CIRA
LPW imagery. However, neutral to unfavorable deep layer wind
shear in its vicinity limits the convection to scattered showers
and isolated tstms from 11N-17N between 64W and 70W. Fresh to
strong E to SE winds are in the vicinity of the trough between 67W
and 75W. Moderate E to SE winds are elsewhere. Trade winds will
remain across much of the south-central Caribbean through late
Tuesday as high pressure builds north of area.
Isolated showers are across the Island due in part to daytime
heating but also due to divergent flow aloft between an upper
anticyclone over the southeast Gulf of Mexico and an upper low E
of the Bahamas. The pattern will be similar through mid week.
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. Elsewhere, the remainder of
the central and eastern Atlc is under the influence of a surface
ridge anchored by a 1025 mb high centered SE of the Azores Islands.
A surface trough is evident into the ridge from 23N44W to 16N48W
with no convection. See special features and tropical waves
sections for more information.
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