[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181720
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...TROPICAL WAVES...

The axis of a tropical wave is near 25W from 02N to 14N,
moving westward at 10-15 kt. Scattered moderate convection is
from 10N to 13N between 20W and 28W.

The axis of a tropical wave is near 45W from 02N to 16N,
moving westward at 10-15 kt. Scattered showers are from 05N-10N
between 40W-45W.

The axis of a tropical wave is near 59W south of 16N, moving
westward at 10-15 kt. No significant convection is noted at
this time with this wave.

The axis of a tropical wave is near 81W south of 17N, moving
westward at 10-15 kt. Scattered moderate convection is noted
from 15N-18N between 79W-84W.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends off the coast of Africa near 17N16W to
07N24W. The ITCZ continues from 06N30W to 06N43W, then resumes
near 06N47W to 05N53W. In addition to the convection
mentioned above in the Tropical Waves section above, scattered
moderate convection is observed from 04N to 10N between 33W
and 52W.

GULF OF MEXICO...

A stationary front extends across the southern portion of the
basin from 25N80W to 21N91W to 17N93W. Scattered moderate
convection is noted within 100 nm N of the front mainly W of
87W. Latest scatterometer data depicts moderate to fresh
winds within 200 nm N of the front. Seas range between 8-11 ft
across the SW Gulf, while 4-7 ft prevail elsewhere. High
pressure is building across the remainder of the basin in the
wake of the front, centered near 22N97W.

For the forecast, the will drift across the southern Gulf
through Tue. Winds off of Veracruz, Mexico are expected to
diminish today. By late Tue, winds across the Gulf will gradually
veer to the E as the front becomes aligned from just offshore of
the N Yucatan Peninsula through the Straits of Florida and
dissipates. Weak high pressure will dominate the basin for the
remainder of the week.

CARIBBEAN SEA...

Refer to the section above for details on the tropical wave
moving across the basin.

A weak pressure pattern prevails across the Caribbean waters.
Light to gentle winds and seas of 1-3 ft prevail across much of
the Caribbean waters.

For the forecast, a persistent weak pressure gradient across the
Caribbean basin will maintain tranquil marine conditions today. A
cold front across the NW Atlc will move SE 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 tonight through Tue and
then moderate to fresh winds late Wed through Fri.

ATLANTIC OCEAN...

Refer to the section above for details on the tropical waves
moving across the basin.

A cold front extends across the Atlantic waters from near 31N64W
to 25N80W. Moderate to fresh northerly winds are noted behind
the front. Seas with these winds are in the 6-8 ft range.
Gentle to moderate winds prevail within 400 nm SE of the front.
Farther east, another cold front extends from near 31N21W to
27N35W, then becomes stationary from that point to 25N42W. A
surface trough extends from 25N43W to 21N53W. Scattered moderate
convection is observed within 120 nm SE of the cold front.
Elsewhere
over the tropical and subtropical waters north of 20N, light to
gentle winds prevail. Seas are in the 6-7 ft range north of 26N
and between 27W and 40W, and 3-6 ft elsewhere over the open
waters north of 20N. Over the tropical waters south of 20N,
gentle to moderate winds and seas of 4-6 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 over the W Atlantic
will continue moving slowly SE and stall along 23N-24N by late
Wed. Expect fresh to strong N to NE winds behind the front
through this morning. High pres will shift ESE across the W
Atlantic along 31N-32N Tue through Thu while the front stalls
and weakens.

$$

ERA
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