[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 242352
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
752 PM EDT WED AUG 24 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 17.4N 40.6W at 24/2100 UTC
or about 955 nm W of the Cape Verde Islands moving NW at 14 kt.
Estimated minimum central pressure is 990 mb. Maximum sustained
wind speed is 60 kt with gusts to 75 kt. Scattered moderate and
isolated strong convection is from 17N-19N between 38W-41W.
Scattered moderate convection is elsewhere from 14N-21N between
36W-45W. See latest NHC Forecast/Advisory under the AWIPS/WMO
headers MIATCMAT2/WTNT22 KNHC for more details.

A 1009 mb low is centered NE of Puerto Rico near 19N66W moving
W-NW at 15 kt. Low-level streamline analysis indicates a broad
area of low pressure extending from the low center westward as
weak troughing to central Hispaniola. Visible satellite imagery
shows a pair of low-level vorticity centers at each end of the
troughing...the strongest being associated with the 1009 mb low.
Scattered moderate convection is occurring across a large area
from 14N-22N between 59W-66W...and from 18N-23N between 66W-72W.
This system could become a tropical cyclone at any time during the
next few days while it moves W-NW across the SW North Atlc waters
N of Puerto Rico...Hispaniola...and the Bahamas. In addition...
earlier scatterometer data indicated near gale to gale force winds
occurring within 90 nm of the NE semicircle. See latest NWS High
Seas Forecast under the AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC
for more details.

...TROPICAL WAVES...
None.

...ITCZ/MONSOON TROUGH...
The Monsoon Trough extends from the African coast near 16N16W to
12N25W to 14N32W. Scattered moderate convection is from 07N-10N
between 13W-19W.

...DISCUSSION...

GULF OF MEXICO...
An upper level anticyclonic circulation is centered over the SE
CONUS near 33N87W providing much of the Gulf basin with E-SE flow
aloft. At the surface...the upper level ridging supports a ridge
anchored by a 1025 mb high centered across northern Georgia with
axis extending SW to the Texas coast near Galveston and then
southward to a 1023 mb high centered along the Mexico coast near
20N97W. Generally moderate to occasional fresh NE to E winds are
noted at this time and are expected to persist through early
Friday. Otherwise...the remnants of an old frontal boundary is
analyzed as a surface trough across the southern Florida peninsula
to near 25N85W in the SE Gulf. This weak boundary is providing
focus for scattered showers and tstms occurring across the Florida
peninsula and eastern Gulf waters from 22N-29N E of 86W. Another
are of scattered showers and tstms in association with maximum
daytime instability is occurring N of 26N between 86W-91W. Looking
ahead...as the Special Features low tracks W-NW...global models
differ in solutions at this time with the GFS weaker and tracking
to the Florida peninsula by Sunday night and then northward along
the eastern peninsula coast Monday...and the ECMWF stronger as it
approaches the southern Florida peninsula Saturday night into
Sunday and into the eastern Gulf waters by Sunday night into Monday.

CARIBBEAN SEA...
The primary concern for the Caribbean is the Special Features low
pressure area NE of Puerto Rico this evening. As the low tracks
W-NW during the next 24-36 hours...plentiful precipitation is
expected across the Leeward Islands...Puerto Rico...US/UK Virgin
Islands...and Hispaniola with localized flooding and mud slides
possible. Otherwise...convection associated with the low is
enhanced due to an upper level anticyclonic circulation centered
over the eastern Caribbean near 18N64W. Farther west...drier air
is noted on water vapor imagery with most of the central Caribbean
experiencing clear skies and fair weather this evening. For the
western Caribbean...an upper level low is centered over Central
America near 18N89W. This upper level feature along with daytime
heating and instability is generating scattered showers and
isolated tstms generally W of 80W. Slightly stronger convection is
noted across northern Guatemala and the Yucatan peninsula.
Although the trades are disrupted due to the Special Features low
pressure area...overall E to NE winds remain within moderate to
fresh S of 15N between 67W-81W.

...HISPANIOLA...
Scattered showers and tstms associated with surface troughing and
the Special Features low pressure area in the vicinity of Puerto
Rico are approaching and are expected to pass N of the island
during the next 24-36 hours. Gusty winds...heavy rainfall...
flash flooding...and mud slides are possible across the island
through Saturday.

ATLANTIC OCEAN...
Aside from Tropical Storm Gaston and the Special Feature low
pressure area...an upper level trough is noted on water vapor
imagery with axis extending from 35N70W to 29N74W. This troughing
supports a stationary front analyzed from 32N66W SW to 29N74W then
SW as a surface trough or possibly shear line to the southern
Florida peninsula near 26N80W. Within the vicinity of the front...
the remnant of Fiona is centered near 29N68W as a 1015 mb low.
Scattered showers and tstms are occurring within 150 nm either
side of the boundary...and from 27N-33N between 58W-69W. Farther
east...an upper level low is centered over the central Atlc near
26N52W and supports a surface trough analyzed from 26N51W to
31N45W. Scattered showers and isolated tstms are occurring within
180 nm W of the boundary as it continues drifting westward.
Otherwise...the remainder of the eastern Atlc is under the
influence of a surface ridge anchored by a 1026 mb high centered
SW of the Azores near 37N34W. Fresh to strong N-NE winds are
expected in the waters between the Canary Islands and Cape Verde
Islands through Friday between the ridge and lower pressure across
West Africa.

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

$$
HUFFMAN
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