[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 272354
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
754 PM EDT SAT AUG 27 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
2315 UTC.

...SPECIAL FEATURES...
Tropical Storm Gaston is centered near 29.2N 54.0W at 27/2100 UTC
or about 585 nm ESE of Bermuda moving NW at 8 kt. Estimated
minimum central pressure is 993 mb. Maximum sustained wind speed
is 60 kt with gusts to 75 kt. Scattered moderate convection is
from 26N-32N between 50W-58W. See latest NHC Forecast/Advisory
under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more
details.

A 1009 mb low is centered across the Florida Straits near 23N79W
moving W-NW at 10-15 kt. A surface trough is analyzed from the NW
Bahamas near 26N77W through the low center to 21N80W. Scattered
moderate convection is occurring across a large area of the SW
North Atlc and Caribbean Sea...including inland portions of
Hispaniola and Cuba this evening. As the low moves W-NW during the
next couple days...increased probability of heavy rainfall...
localized flooding...and mud slides are possible across those
areas. In addition...heavy rainfall and flooding in possible
across the southern Florida peninsula as the low moves into the
Gulf of Mexico by Sunday night into Monday.

...TROPICAL WAVES...
Tropical wave extends from 10N29W to 17N25W moving W at 10-15 kt.
The wave is embedded within the Monsoon Trough axis and is
difficult to track. Position is based on interpolation. No
significant deep convection is occurring with the wave at this
time.

Tropical wave extends from 11N85W to 21N83W moving W at 15-20 kt.
A portion of energy associated with the wave fractured north a
couple days ago and is now analyzed as a 1009 mb low and surface
trough extending across the NW Bahamas and central Cuba. The
remaining westward moving wave energy however is noted in global
model data as 700 mb troughing and 850 mb relative vorticity
fields S of 20N between 80W-87W. Isolated moderate convection is
from 13N-19N between 82W-87W.

...ITCZ/MONSOON TROUGH...
The Monsoon Trough extends from 16N17W to 07N41W. The
Intertropical Convergence Zone axis extends from 07N41W to
03N51W. Scattered moderate convection is from 10N-17N between
14W-18W...and from 05N-08N between 48W-52W. Isolated moderate
convection is within 240 nm S of the axis between 18W-38W.

...DISCUSSION...

GULF OF MEXICO...
An upper level low is noted on water vapor imagery over the NW
Gulf near 27N95W that supports a weak surface trough analyzed from
24N90W to the Texas coast near Galveston. Widely scattered showers
and tstms are occurring N of 28N between 90W-96W...including
inland portions of eastern Texas and much of Louisiana. Over the
eastern Gulf...an upper level anticyclonic circulation is centered
near 28N84W with favorable lifting mid-level dynamics collocated
with the ridging. Together...these two features are generating
scattered showers and tstms across much of the eastern Gulf E of
90W and across portions of the southwestern Florida peninsula S of
28N. This overall synoptic pattern is expected to persist through
Sunday night as a fractured portion of energy associated with a
tropical wave currently in the western Caribbean Sea moves across
the Florida Straits and into the SE Gulf waters by Monday.
Increased precipitation with locally heavy rainfall and possible
localized flooding is anticipated this weekend across the southern
Florida peninsula and Florida Keys.

CARIBBEAN SEA...
The western half basin is under the influence of lower surface
pressure values given a tropical wave currently analyzed along 85W
and the northern energy of the wave that has fractured north and
remains focused on a 1009 mb low centered across the Florida
Straits near 23N79W. The tropical wave is providing focus for
scattered showers and tstms in the vicinity of 17N85W and across
inland portions of Honduras and Nicaragua this evening. Other
convection...supported by favorable mid-level dynamics is
occurring across the Greater Antilles region stretching from the
Mona Passage W-NW to across Cuba. Scattered showers and tstms are
occurring N of 15N between 67W-77W...and N of 20N between 77W-85W.
This complex tropical wave and associated energy to the north is
expected to continue W-NW through Sunday and likely bring an
increased probability of precipitation to Central America and the
Yucatan peninsula with potential for locally heavy rainfall...
localized flooding...and mud slides across the region. Farther
east...moderate to fresh trades will re-establish themselves E of
80W on Sunday and increase to fresh to strong across the central
Caribbean by Monday night into Tuesday.

...HISPANIOLA...
Scattered showers and tstms associated with the broad low
pressure area NW of the island are expected to persist through the
overnight period into Sunday as the low moves W-NW during the
next 24 hours. Gusty winds...heavy rainfall...flash flooding...
and mud slides are possible across the island through Sunday.

ATLANTIC OCEAN...
Aside from Tropical Storm Gaston...a 1009 mb low is centered
across the Florida Straits near 23N79W moving W-NW at 10-15 kt.
Low-level streamline analysis indicates surface troughing
extending from SW of Bermuda as a 1010 mb low near 31N67W SW
through the Florida Straits low to the broad area of low pressure
across the western Caribbean Sea focused on a tropical wave along
85W. A large area of scattered showers and tstms are occurring
from across Hispaniola and Cuba mainly S of 27N W of 70W. With
regards to the 1010 mb low centered near Bermuda...most of the
ongoing scattered showers and tstms are occurring within the
NE periphery of an upper level low centered near 31N73W from 31N-
34N between 66W-70W. The low is expected to drift westward through
Monday. Lastly...the eastern Atlc is under the influence of a
surface ridge anchored by a 1025 mb high centered near 40N33W. A
weak surface trough is analyzed on the southern periphery of the
ridging from 22N33W to 28N34W. Isolated showers are possible
within 180 nm either side of the trough axis.

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

$$
HUFFMAN
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