[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291754
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Fri Oct 29 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.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: Strong to gale force W to NW winds
will continue over the northern Gulf of Mexico through today,
especially from 27N to 29N, between 85W and 92W. Winds will
diminish below gale force this evening, then gradually diminish to
less than 15 kt by late Saturday night or early Sunday morning.
Wave heights of 15 to 22 ft are expected to continue over
portions of the Gulf in W to NW swell, subsiding to 10 to 17 ft
after midnight tonight. The large NW swell will spread southeast,
gradually decaying through the weekend. Please see the latest NWS
High Seas Forecast issued by the National Hurricane Center at
website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for
further details.

...TROPICAL WAVES...

A tropical wave is in the Atlantic Ocean along 30W from 04N to
18N, moving W at 5-10 kt. Any nearby convection is described in
the next section.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coastal border of Guinea and
Guinea-Bissau near 11N15W to 08N23W to 1012 mb low pressure near
07N32W to 06N38W. The ITCZ continues from 06N38W to 07N54W. A
large area of scattered moderate and isolated strong convection
is noted from 00N to 15N between 07W and 35W.

GULF OF MEXICO...

Please see the Special Features section for information on the
forecast for the gale force winds and dangerous seas across the
northern Gulf of Mexico.

The cold front exited the Gulf of Mexico and extends from Grand
Bahama Island to the Isle of Youth to southern Belize as of 1500
UTC. Gale force winds are still occurring in the northern Gulf.
The latest ASCAT pass from the late morning hours on Friday shows
near gale to gale force winds of 30 to 35 kt covering the area
from 26N to 30N between 84.5W and 94W. An oil platform KGBK near
27.2N 92.2W measured winds of 34 kt gusting to 42 kt at a height
of 58 meters at 1515 UTC. NOAA buoy 42039 at 28.8N 86.0W measured
wave heights of 15 ft at 1550 UTC today. Winds over 25 kt and seas
over 13 ft are mainly confined to areas north of 24N. The
quietest conditions in the basin are currently found in the south-
central Bay of Campeche and SW Gulf of Mexico, where moderate N
winds and seas of 4 to 6 ft prevail.

For the forecast, conditions will improve Sun as ridging
dominates from near the Texas-Louisiana border to the Bay of
Campeche with light to gentle winds across the basin. Seas of 3 ft
or less are expected for the start of next week.

CARIBBEAN SEA...

As of 1500 UTC, a cold front extends from western Cuba near 23N82W
to southern Belize near 16N89W. Scattered moderate thunderstorms
are noted within 30 nm behind and within 150 nm ahead of the
front. The latest ASCAT pass shows fresh to strong N winds to the
west of the cold front, especially over the western Gulf of
Honduras and areas along the coast, south of Cozumel. Seas are
quickly building in the Yucatan Channel behind the cold front.
Seas in the Yucatan Channel are forecast to peak tonight in the 10
to 14 ft range in NW swell, before gradually subsiding to below 8
ft by Sunday afternoon.

Elsewhere, scattered moderate thunderstorms are seen from 20N-
21N between 78W-79W, and also along the coast of Nicaragua and
eastern Honduras. The east Pacific monsoon trough is enhancing
scattered moderate to strong convection offshore eastern Panama
and NW Colombia. Isolated moderate convection is also seen in the
south-central Caribbean, south of 14N and west of 67W. Moderate
trades cover most of the basin east of 82W, except for fresh in
the south-central Caribbean, south of 16N between 67W-74W, while
gentle winds prevail in the far SW basin. Most of the eastern and
central Caribbean is currently experiencing seas of 3 to 6 ft.

For the forecast, the cold front will continue advancing through
the NW Caribbean this weekend, before stalling Sun night from
eastern Cuba to Nicaragua. Moderate to fresh NW winds and seas of
up to 12 ft are expected in the wake of the cold front,
especially in and near the Yucatan Channel. Elsewhere, a weak
ridge over the northern Caribbean Sea ahead of the front will
support mainly gentle to moderate trade winds across the basin,
with locally fresh winds likely off the coast of Venezuela.

ATLANTIC OCEAN...

As of 1500 UTC, a cold front extends from 31N76W to Grand Bahama
Island near 27N78W to the coast of Cuba near 23N82W to southern
Belize near 16N89W. A line of strong thunderstorms is ahead of the
front, and extends from 31N72W to 24.5N79W as of 1700 UTC. The
latest ASCAT pass from Friday morning shows fresh to strong winds
on both sides of the front, covering the area north of 24N and
west of 71W. Wave heights of 7 to 10 ft cover the area to the
north of the Bahamas.

For the forecast west of 65W, the cold front will move slowly
east and reach a Bermuda to eastern Cuba line over the weekend.
Fresh to strong winds are expected on both sides of the front into
Sat night, mainly north of 26N. Seas of 8 ft or greater will fill
across the northern waters today, lingering through Sun before
decaying. The front will weaken as it stretches from 30N65W to the
Turks and Caicos Islands early Mon with gentle to moderate NE
flow then prevailing through Tue night.

In the eastern and central Atlantic, a surface ridge extends from
a 1021 mb high pressure near 29N21W to a 1018 mb high pressure
near 24N50W to Hispaniola. Light to gentle winds are within a
couple hundred nm of the surface ridge axis. A cold front extends
from 31N54W to 29N58W. Isolated moderate thunderstorms are well
southeast of the front. Fresh to strong SW winds are occurring
east of the front, mainly north of 28.5N. Seas of 8 to 12 ft,
mainly in NW to N swell, are occurring north of 26N and west of
44W. The swell is emanating from a gale force 983 mb low, well
north of the area near 41N55W. Seas of 4 to 7 ft prevail
elsewhere. Across the tropical latitudes, gentle to moderate
trades prevail, except for fresh to strong NE winds east of 35W
from 12N to 20N.

For the forecast east of 65W, the cold front from 31N54W to 29N58W
will reach from 31N40W to 27N47W early Sun, before slowing down
and becoming nearly stationary through early next week. Fresh to
strong SW winds will continue ahead of the front through early
next week, with seas of 8 to 11 ft in the region.

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. A volcanic ash
cloud is slowly drifting southwest. High volcanic ash
concentration remains in the vicinity of 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/.

$$
Hagen
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