[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180601
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Mon Oct 18 2021

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: A cold front extends from southwest
Florida to 22N90W and to the eastern Bay of Campeche. A tight
gradient behind the front from high pressure that is building
southward over eastern Mexico is producing northwest to north
gale-force winds of 30-35 kt offshore Veracruz, Mexico along with
peak seas of up to 15 ft. The gradient will slacken just enough to
allow for these winds to diminish to just below gale force
in just a few hours. Marine conditions will continue to improve
through early this week.

Please read the latest High Seas Forecast issued by the National
Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details
on both warnings.

...TROPICAL WAVES...

The axis of a far eastern Atlantic tropical wave is near 21W/22W
from 02N to 17N. It is moving westward at 10-15 kt. Scattered
moderate convection is within 120 nm west of the wave from 08N to
10N.

The axis of a central Atlantic tropical wave is near 43W from 02N
to 19N, moving westward at 10-15 kt. Increasing scattered
moderate to isolated strong convection is noted within 180 nm east
of the wave axis from 08N to 10N. The latest CIRA LPW animation
imagery indicates an enhancement of the atmospheric moisture in
that same area. Scattered moderate convection is within 120 nm
west of the wave axis from 05N to 06N.

The axis of another central Atlantic tropical wave is near 56W
south of 20N, moving westward at 10-15 kt. Scattered moderate
convection is seen from 18N to 20N betwen 51W-54W, mainly
associated with a sharp upper-level trough north of the tropical
wave.

The axis of a Caribbean Sea tropical wave is estimated to be
near 76W south of 20N. It is moving westward at 10-15 kt.
Small isolated showers and thunderstorms are within 60 nm
E of the wave axis south of 13N.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends off the coast of Africa near 12N17W to
07N23W. Segments of the ITCZ extends from 07N23W to 08N43W and
also from 08N44W to 06N50W. In addition to the convection
mentioned above in the Tropical Waves section, scattered moderate
to isolated strong convection is south of the ITCZ from 05N to 08N
between 35W-39W. Scattered moderate convection is within 120 nm
south of the ITCZ between 45W-47W.

GULF OF MEXICO...

Refer to the Special Features for information on the Gale Warning
in the far SW Gulf of Mexico off the coast of Veracruz, Mexico.

A cold front extends from southwest Florida to 22N90W and to the
eastern Bay of Campeche. Aside from the gale-force winds offshore
the coast of Veracruz, Mexico, fresh to strong winds prevail west
of the front. Seas west of the front are in the 8-13 ft range
south of about 22N, except peaking to 15 ft off Veracruz. Seas
are 5-7 ft elsewhere west of the front, and 2-4 ft east of the
front. Scattered showers and a few thunderstorms are over the
extreme southern Bay of Campeche south of 19N and between 94W-95W.

For the forecast, the aforementioned cold front will continue
moving southeastward through Mon. Winds off of Veracruz, Mexico
are expected to diminish through Mon. Winds across the Gulf will
gradually veer to the east late Mon through Tue as the front
becomes aligned from just offshore of the northern Yucatan
Peninsula through the Straits of Florida and dissipates.

CARIBBEAN SEA...

A weak pressure pattern prevails across the Caribbean waters.
Scattered showers and thunderstorms are occurring well inland
Nicaragua and over southwestern Honduras. Similar activity is
over the eastern section of Haiti. Otherwise, small isolated
showers and thunderstorms are over some areas of the western
Caribbean and over the northeastern Caribbean within about 90 nm
south of Puerto Rico. Gentle to moderate winds and seas of 2-4
ft are noted over the central and eastern Caribbean waters south
of 15N. Light to gentle winds and seas of 1-3 ft prevail
elsewhere across the Caribbean.

For the forecast, the weak pressure gradient across the Caribbean
basin will lead to tranquil marine conditions through Mon. A cold
front across the NW Atlantic will move southeastward through
early Wed before stalling from near 25N65W to the Straits of
Florida. High pressure building in the wake of the front will
bring a return to moderate trade winds to the Caribbean Mon night
through Tue and then moderate to fresh winds late on Wed.

ATLANTIC OCEAN...

A cold front extends across the Atlantic waters from near 31N71W
to South Florida. Fresh to strong north to northeast winds as
were revealed in a recent ASCAT are behind the front. Seas with
these winds are in the range of 6-8 ft. Farther east, a cold
front extends from near 31N32W to 25N42W, then becomes stationary
to 23N47W and transitions to a trough to near 20N54W. A weak
trough is east of the cold front along a position from 29N27W to
23N35W. No significant convection is noted. A sharp mid to upper-
level trough just to the northwest of these features is supporting
scattered moderate convection observed from 15N to 20N betwen
52W- 57W. Mainly fresh southwest winds and seas of 8-9 ft in a
southwest swell are also noted within 180 nm east of the front,
north of 28N. Over the tropical waters south of 20N, moderate to
fresh winds and seas of 4-6 ft prevail. N of 20N and east of 50W,
gentle to moderate winds and seas of 5-8 ft remain there.
Elsewhere over the tropical and subtropical waters north of 20N
and west of 50W, light to gentle winds, and seas of 3-5 ft,
prevail.

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Light to
moderate volcanic ash is expected in the area east of the
volcano, while high ash concentrations are close to the volcano.
Marine and aviation interests should monitor this ongoing
situation by reading the Volcanic Ash Advisory issued by Meteo-
France at http://vaac.meteo.fr/volcanoes /la-palma/

For the forecast west of 65W, the cold front that extends from
near 31N71W to South Florida will will continue moving southeastward
reaching from near Bermuda to the Straits of Florida this morning.
Expect fresh to strong north to northeast winds behind the front
through this morning. High pres will shift east-southeastward
across the western Atlantic along 31N-32N Tue through Wed while
the front stalls from near 25N65W to the Straits of Florida.

$$
Aguirre
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