AXNT20 KNHC 302349
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
749 PM EDT FRI SEP 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 1800 UTC surface analysis and satellite imagery through
Hurricane Matthew is centered near 13.5N 72.0W at 01/0000 UTC or
about 70 nm NNW of Punta Gallinas Colombia and about 380 nm SE of
Kingston Jamaica moving WSW at 8 kt. Estimated minimum central
pressure is 945 mb. Maximum sustained wind speed is 130 kt with
gusts to 160 kt. Scattered to numerous strong convection is from
12N-15N between 68W-73W. Scattered moderate and isolated strong
convection is elsewhere from 11N-16N between 67W-74W. See latest
NHC Intermediate Public Advisory under AWIPS/WMO headers
MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under AWIPS/
WMO headers MIATCMAT4/WTNT24 KNHC for more details.
Tropical wave extends from 12N32N to 19N30W moving W at 10 kt.
The wave coincides with broad 700 mb troughing S of 20N between
28W-37W and a maximum in 850 mb relative vorticity in the vicinity
of the wave axis between 28W-34W. In addition...a weak 1010 mb low
is noted along the axis near 13N that remains embedded within the
Monsoon Trough axis. No significant convection is associated with
the wave at this time.
Tropical wave extends from 13N50W to 23N51W moving W at 10-15 kt.
The wave is embedded within broad 700 mb troughing between 42W-
56W...and a maximum in 850 mb relative vorticity between 48W-55W.
A 1009 mb low is centered at the southern extent of the wave axis
near 13N. Scattered moderate and isolated strong convection is
from 11N-17N between 44W-50W. Widely scattered moderate convection
is elsewhere from 13N-21N between 37W-46W.
The Monsoon Trough extends from the African coast near 09N13W to
14N31W. Scattered moderate and isolated strong convection is from
10N-13W between 14W-17W.
GULF OF MEXICO...
A broad deep layered low is centered over much of the Ohio River
valley this evening with troughing dipping southward over the
eastern Gulf to a broad base over the NW Caribbean Sea. The
trough supports a stationary front extending across the northern
Florida peninsula to 28N83W to 27N90W to 23N97W. Scattered showers
and isolated tstms are occurring across the SW Gulf generally S of
the front W of 94W and is likely enhanced due to an upper level
diffluent environment between the troughing and an upper level
anticyclone centered over west-central Mexico. A few other area of
isolated showers are occurring across the remaining southern Gulf
waters...however the strongest convection this evening remains
across interior portions of the the Florida peninsula and Florida
straits in the adjacent waters north of Cuba. N of the front...
mostly clear skies prevail as a surface ridge remains anchored
across Oklahoma and the ARKLATEX region. The front is expected to
gradually become diffuse through the weekend into early next week
with light to gentle E-NE winds expected as ridging slides
eastward to the N across the SE CONUS.
The main concern is Hurricane Matthew located in the central
Caribbean. An upper level ridge covers much of the Caribbean E of
80W while an upper level trough axis extends from over western
Cuba S-SW to over western Honduras this evening. The upper level
troughing is supportive of scattered showers and isolated tstms
across the NW Caribbean with stronger convection occurring across
inland portions of western Cuba...Guatemala...Belize...and the
Yucatan peninsula. Across the SW Caribbean...the Monsoon Trough
axis extends along 10N from northern Colombia to Costa Rica and is
providing focus for scattered showers and tstms occurring S of 13N
between 75W-85W. Otherwise as Matthew tracks across the central
Caribbean through early next week...the trades will continue to be
disrupted through Tuesday when Matthew is expected to be centered
north of eastern Cuba in the SW North Atlc region. Trades will
begin re-establishing themselves from east to west thereafter
through the second half of next week.
High level cloudiness continues moving over the island this
evening as Matthew remains centered well south of Hispaniola.
Isolated showers and tstms are possible across the island through
the overnight hours into Saturday. Matthew is expected to
continue on a westerly track through late Saturday before making a
turn toward the northwest then north late in the weekend.
The deep layered trough over the eastern Gulf of Mexico extends
over the far western portions of the SW North Atlc west of 75W
supporting a cold front extending from 33N79W to 31N80W then
becomes stationary to the Florida peninsula near 29N81W. Skies
are clear W of the front with scattered showers and isolated
tstms N of 25N W of 73W. The remainder of the Atlc is under the
influence of a surface ridge anchored by a 1026 mb high centered
near 40N31W that extends an axis SW to 32N45W then W to Bermuda
near 32N65W. The surface ridging is expected to persist through
the weekend as Matthew moves through the Caribbean Sea. Then as
Matthew begins its northward track...the ridge will shift east as
Matthew moves into the SW North Atlc by early Tuesday.
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