[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 101640
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Fri Dec 10 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
1640 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough remains confined to the African continent,
reaching inland Sierra Leon near 08N11W. The ITCZ begins off the
coastal boarder between Sierra Leon and Liberia near 06N12W and
extends westward to 04N25W and then southwest to the coast of
Brazil near 02N45W. Scattered moderate convection is noted near
the ITCZ axis from 04N to 07N and between 16W and 34W.

GULF OF MEXICO...

High pressure ridging into the area dominates the weather pattern,
suppressing any significant convection. Winds are strongest in
the western Gulf of Mexico with a strong southerly breeze and 4-6
ft seas noted offshore near the Texas/Mexico boarder. A fresh S-SE
breeze with 3-5 ft seas are noted encompassing the majority of
the basin west of 90W. East of 90W, winds are SE gentle to
moderate with 2-4 ft seas.

For the forecast, the high pressure ridge will gradually shift
eastward through Sat afternoon in response to a strong cold front
that will move over the NW Gulf on Sat. Moderate to fresh
southerly return flow will set-up across the western and central
Gulf beginning late Fri ahead of the front. Fresh to strong
northerly winds and building seas are expected in the wake of the
front through Sat night. The front will weaken as it reaches from
central Florida to the SW Gulf Sun and dissipate by Mon. Fresh to
strong east winds will spread westward through the Straits of
Florida and to the eastern Gulf S of 26N Mon through Tue night
along with building seas.

CARIBBEAN SEA...

The gradient between the subtropical high and low pressure over
Colombia is maintaining enhanced easterly trade wind flow through
the basin. Winds are moderate to fresh in the eastern Caribbean
with 5-7 ft seas. Winds are fresh to strong in the central
Caribbean with 6-8 ft seas including a strong northeasterly
breeze near the coast of Colombia with seas reaching up to 9 ft.
In the northwest Caribbean, winds are moderate to fresh with 3-5
ft seas. Dry and stable atmospheric conditions are limiting any
significant convection in the basin.

For the forecast, the pressure gradient will continue to support
fresh to strong easterly trades over the south-central Caribbean
through the weekend. Moderate to fresh trades will prevail
elsewhere. High pressure will continue to strengthen over the
western Atlantic today resulting in fresh to locally strong
northeast winds in the Windward Passage, the lee of Cuba and south
of Hispaniola through Tue night.

ATLANTIC OCEAN...

Recent scatterometer data has confirmed the presence of a
shearline in place of an old stationary front in the NW Atlantic
along the axis from 29N72W to 31N64W with a fresh to strong
northerly breeze north of the boundary and a light to gentle
breeze to the south. Elsewhere in the NW tropical Atlantic, a
moderate to fresh easterly breeze prevails with 6-8 ft seas. Sea
heights gradually increase to the east with 8-10 ft seas
prevailing east of 50W. East of 35W, winds are fresh to strong
from the northeast with near gale force gusts near the Canary and
Cabo Verde Islands. Seas in the area are predominantly 10-12 ft.

For the forecast west of 65W, the stationary front will dissipate
through tonight. High pressure will build across the region in
the wake of the front, producing moderate to fresh NE to E winds S
of 22N, and mainly gentle to moderate winds N of 22N through Sat
night. The next cold front will move off the northeast Florida
coast early Sun, and reach from near 31N65W to South Florida by
Sun night. This front is forecast to dissipate over the
southeastern waters on Mon. High pressure behind the front will
bring fresh to strong northeast to east winds mainly across the
waters south of 27N by Mon night. These conditions are expected to
last through Tue night.

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Low ash
concentrations are expected in the vicinity of the volcano with
very low concentrations to the southwest. 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/.

$$
FLYNN
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