[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 222345
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
744 PM EDT Sun Oct 22 2017

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...
A cold front is currently analyzed across the NW Gulf waters from
the SW coast of Louisiana near 30N93W to the Texas coast near
Corpus Christi. The front is forecast to sweep across the Gulf
through Monday night with near gale to gale force N to NW winds
expected to materialize S of 21N W of 95W by 23/1800 UTC and
persist for 12 hours as the pressure gradient remains strong.
Please see the latest NWS High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.

...TROPICAL WAVES...
A tropical wave extend from 06N51W to 17N48W moving W at 5-10 kt.
The wave coincides with 700 mb troughing between 42W-52W and a
maximum in 850 mb relative vorticity to the east of the axis near
11N47W. Scattered moderate convection is from 07N-17N between
38W-50W and continues to be enhanced by a middle to upper level
trough with axis extending from 25N40W SW to a broad base over
northern Guyana.

A tropical wave extend from 10N89W to 20N89W moving W at 10-15
kt. The wave coincides with 700 mb troughing between 84W-94W and a
maximum in 850 mb relative vorticity along the wave axis near 18N.
Scattered moderate convection is from 12N-23N between 85W-92W.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 10N14W to
08N20W. The Intertropical Convergence Zone axis extends from 08N20W
to 04N40W to 06N50W. Isolated moderate convection is from 03N-06N
between 13W-18W.

...DISCUSSION...

GULF OF MEXICO...
A vigorous middle to upper level trough is progressing eastward
over the lower Mississippi River valley this evening and supports
a cold front extending from the Arklatex region to the SW
Louisiana coast near 30N93W to the Texas coast near Corpus Christi
then inland across northern Mexico. A leading outflow boundary
extends east of the cold front from 30N90W to 28N92W to 27N97W.
Low-level moisture convergence and middle to upper level
divergence is generating scattered showers and tstms primarily
across the eastern Gulf waters N of 25N between 82W-90W.
Additional isolated showers are occurring N of 25N W of 90W.
Farther south...the northern extent of a tropical wave along 90W
is providing focus for scattered showers and tstms S of 24N
between 83W-96W. Most of this convection is also enhanced due to
upper level divergence on the northern periphery of an upper level
ridge centered over the NW Caribbean Sea near 20N85W. Otherwise...
the cold front is expected to sweep across the basin through
Tuesday. As the front passes across the western Gulf...the Special
Features near gale to gale force winds are anticipated within a
broader fresh to strong northerly wind field that will spread
eastward in wake of the front. Strong high pressure will settle
in across the southern Plains and move out across the western Gulf
by Wednesday night into Thursday.

CARIBBEAN SEA...
The combination of a tropical wave along 90W...a surface trough
extending from the Gulf of Honduras SW to the offshore waters of
Nicaragua near 12N83W...and a favorable upper level divergent
environment over much of the western Caribbean anchored near
19N84W are supportive of scattered showers and strong tstms
occurring W of a line from western Cuba through 17N80W to northern
Colombia coast near 11N74W...including much of Central America.
Most of the western Caribbean falls within moderate to fresh
trades while farther east...fresh to strong trades prevail as a
strong pressure gradient remains in place due to strong high
pressure anchored across the western North Atlc.

...HISPANIOLA...
Dry air aloft within NW flow will support fair weather across the
island through Monday. Fresh to strong trades are expected through
Monday night and will diminish into moderate to occasional fresh
levels on Tuesday.

ATLANTIC OCEAN...
Much of the SW North Atlc is under the influence of a surface
ridge anchored by 1034 mb high centered over the Canadian
Maritimes near 47N64W. The southern periphery of this ridge is
providing moderate to fresh E-SE winds W of 65W. Farther east...an
upper level low is centered near 26N64W. In addition...a longwave
trough over the central North Atlc is supporting a cold front from
32N45W SW to 30N50W then becomes a stationary front to near the
upper level low around 28N63W. Scattered showers and isolated
tstms are occurring within 150 nm either side of the front...and
from 22N-30N between 60W-66W in association with the upper level
low. The remainder of the eastern Atlc is under the influence of
another surface ridge anchored by a 1030 mb high centered W of the
Iberian peninsula near 40N14W.

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

$$
HUFFMAN
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