[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 182355
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
755 PM EDT THU AUG 18 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 Fiona is centered near 17.0N 41.3W at 18/2100 UTC
or about 994 nm W of the Cape Verde Islands moving NW at 9 kt.
Estimated minimum central pressure is 1006 mb. Maximum sustained
wind speed is 40 kt with gusts to 50 kt. Scattered moderate
convection is from 16N-21N between 39W-43W. See latest NHC
Forecast/Advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC
for more details.

...TROPICAL WAVES...
Tropical wave extends from 12N28W to 20N28W moving W at 15-20 kt.
A 1009 mb low is centered at the southern extent of the wave that
remains embedded within the Monsoon Trough. The wave coincides
with 700 mb troughing between 25W-32W with 850 mb relative
vorticity maximized along the wave axis near 13N and in the
vicinity of the low. Scattered moderate from 08N-12N between 24W-
34W.

Tropical wave extends from 09N56W to 15N56W moving W at 20 kt.
The wave remains low amplitude with associated 700 mb troughing
noted on global model data between 54W-59W. Isolated moderate
convection is from 10N-12N between 54W-60W.

Tropical wave extends from 12N71W to 19N70N moving W at 15-20 kt.
The wave coincides with subtle 700 mb troughing between 69W-74W on
the southwestern periphery of a mid-level ridge anchored over the
Atlc near 24N62W. Isolated moderate convection is from 15N-17N
between 70W-73W.

Tropical wave extends from 11N95W to 20N95W moving W at 15-20 kt.
Most of the energy associated with the wave is noted in the East
Pacific region...however isolated moderate convection is
occurring from 16N-22N between 94W-97W.

...ITCZ/MONSOON TROUGH...
The Monsoon Trough extends from the African coast near 14N17W to
11N22W to 11N32W. The Intertropical Convergence Zone axis extends
from 10N44W to 07N58W. Aside from convection associated with the
tropical waves...isolated moderate convection is from 08N-13N
between 10W-24W...and from 09N-12N between 46W-54W.

...DISCUSSION...

GULF OF MEXICO...
NE flow aloft prevails over the Gulf this evening between an upper
level ridge axis extending from west-central Mexico near 23N106W
to over the SE CONUS near 33N85W and an elongated upper level low
centered over the SE Gulf near 25N85W. Mostly dry air and overall
stability is noted across the basin...however diffluence aloft is
maximized over the the NW waters and inland portions of Louisiana
and Texas supporting scattered showers and tstms mainly N of 28N W
of 89W. Otherwise...the remainder of the basin is under the
influence of a weak surface ridge anchored by a 1020 mb high
centered across the Florida panhandle near 31N86W. Mostly gentle
to moderate E-SE winds persist and are expected through the
weekend ahead.

CARIBBEAN SEA...
Water vapor imagery indicates mostly dry air and stable
conditions aloft generally E of 83W with the exception of moisture
associated with a tropical wave currently analyzed along 71W. W of
83W...scattered showers and tstms are occurring across inland
portions of Central America and are likely enhanced due to an
upper level anticyclone centered near 13N84W and the associated
upper level diffluence. Otherwise...mostly clear skies prevail as
generally fresh to strong trades prevail between 70W-80W.

...HISPANIOLA...
Dry and stable air aloft is noted on water vapor imagery over the
islands this evening even with the current passage of a tropical
wave axis along 71W. Showers and tstms associated with the wave
remain well south of the island across the central Caribbean Sea.
Otherwise...as the wave passes to the SW...mostly fair skies are
anticipated through the overnight hours into Friday.

ATLANTIC OCEAN...
The main feature over the SW North Atlc this evening is an upper
level anticyclonic circulation centered near 23N63W. Diffluent
flow on the northern periphery of the ridging is supporting
scattered to numerous showers and scattered tstms from 24N-30N
between 59W-67W. This activity also focuses on a weak surface
trough analyzed from 26N70W to 29N65W. Otherwise...the remainder
of the SW North Atlc is under the influence of weak surface
ridging and a weak upper level low centered near 30N75W. Isolated
showers and tstms are possible across the NW Bahamas and adjacent
coastal waters this evening. Farther east...the central and
eastern Atlc are influenced by a surface ridge anchored by a 1019
mb high centered W of the Madeira Islands near 32N21W and a 1020
mb high centered near 27N37W.

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

$$
HUFFMAN
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