[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 090607
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Sat Oct 9 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
0530 UTC.

...SPECIAL FEATURES...

A nearly stationary area of low pressure located about 200 miles
south of Cape Hatteras, North Carolina continues to produce
disorganized showers and thunderstorms. Environmental conditions
could briefly become marginally conducive for the low to acquire
subtropical characteristics by Saturday night and early Sunday.
This low is forecast to begin moving slowly toward the west-
northwest tonight and then northwest on Saturday, bringing the
system closer to the coasts of the Carolinas. Regardless of
development, intermittent periods of locally heavy rains and gusty
winds will affect eastern portions of the Carolinas through the
weekend. There is a medium chance of development for this low
over the next 48 hours. Interests along the Carolina coast should
monitor this system closely and read the latest Tropical Weather
Outlook at https://www.hurricanes.gov and
Mariners can read the High Seas Forecast from the Ocean Prediction
Center at https://ocean.weather.gov for more information.

...TROPICAL WAVES...

An Atlantic tropical wave is near 43W from 16N southward and
moving W at 15 to 20 kt. Scattered moderate convection is seen
from 06N to 09N between 41W and 47W.

A newly analyzed tropical wave is E of the Lesser Antilles along
52W from 18N southwestward and moving W near 10 kt. Scattered
moderate to isolated strong convection is noted from 11N to 14N
between 51W and 57W. It is expected to bring showers and gusty
winds to the Windward Islands Sunday or Monday.

A Caribbean tropical wave is near 70W from the Dominican Republic
southward across NW Venezuela into E central Colombia, and moving
W near 15 kt. Scattered showers and isolated thunderstorms are
occurring over Haiti and N central Venezuela.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends southwestward through the Senegal coast
near 15N17W to 07N25W. The ITCZ continues westward from 07N25W to
07N42W, and then from 07N44W to 06N49W. Scattered moderate
convection is found near the monsoon trough from 04N to 14N
between the Africa coast and 25W. Scattered moderate to isolated
strong convection is present near the ITCZ from 02N to 12N between
25W and 39W.

...GULF OF MEXICO...

A cold front curves southwestward from NE Florida to the E central
Gulf, then continues as a weak stationary front to just N of the
Bay of Campeche. Scattered showers and isolated thunderstorms are
evident up to 50 nm SE of this boundary, including central
Florida. Convergent surface winds S of the stationary front are
triggering similar conditions across the S Bay of Campeche,
including the Mexico coast. Gentle to moderate winds and seas up
to 4 ft are possible near these showers and thunderstorms.
Otherwise, a ridge of high pressure extending southwestward from
S Louisiana/Mississippi to NE Mexico is providing light to gentle
winds with seas at 1 to 3 ft over the N Gulf.

For the forecast, part of the frontal boundary will transition
into a frontal trough overnight, maintaining scattered showers and
thunderstorms over the SE Gulf. The frontal trough will then move
across south Florida and the SE Gulf on Sat while dissipating on
Sun. Moderate to fresh southerly return flow is expected over the
western Gulf late Sun through Wed night under the influence of a
ridge.

...CARIBBEAN SEA...

Modest convergent trade winds are producing isolated thunderstorms
across Cuba and the adjacent waters, and over the SE basin near
the Windward Islands. Refer to the Tropical Waves section for
additional weather in the basin. With weaker pressure gradient,
gentle to moderate ENE trades with seas at 4 to 6 ft are noted
across the E and central basin. Light to gentle ENE trades and
seas of 2 to 4 ft prevail for the W basin.

For the forecast, a tropical wave currently located E of the
Lesser Antilles along 54W/55W is producing fresh to strong winds
and some convective activity. The wave will reach the Lesser
Antilles late Sat, entering the eastern Caribbean by Sat night.
Then, this system is forecast to move across the US/UK Virgin
Islands and Puerto Rico by Sun night into Mon, likely reaching
Hispaniola late on Mon.

...ATLANTIC OCEAN...

A surface trough runs southwestward to the low pressure mentioned
in the Special Features section above to the central Florida
coast. Numerous showers and scattered thunderstorms are flaring up
from S Florida northeastward across the NW Bahamas to SW of
Bermuda. Weak surface troughing is causing scattered showers and
isolated thunderstorms across the central Atlantic from 24N to 31N
between 40W and 66W. Moderate to locally fresh winds and seas up
to 7 ft are possible near these showers and thunderstorms. Refer
to the Tropical Waves and Monsoon Trough/ITCZ sections for
additional convection in the basin.

A modest surface ridge stretches west-southwestward from a 1027
mb Azores high to E of the Bahamas. It is promoting light to
gentle winds with seas at 4 to 6 ft N of 24N between 31W and 70W.
Gentle to locally moderate winds and seas of 4 to 7 ft are found S
of 10N between the Africa and S America coasts. Moderate to fresh
NE to E trades and seas at 6 to 8 ft prevail for the remainder of
the Atlantic Basin.

The Cumbre Vieja volcano, that is on the island of La Palma in
the Canary Islands, has been erupting since 19 September 2021.
Marine and aviation interests should monitor this on-going
situation, by reading the Volcanic Ash Advisory, that is issued by
Meteo-France, at http://vaac.meteo.fr/volcanoes/la-palma/.

For the forecast W of 65W, a nearly stationary area of low
pressure remains N of area about 200 miles south of Cape Hatteras,
North Carolina. This system continues to produce disorganized
showers and thunderstorms. Environmental conditions could briefly
become marginally conducive for the low to acquire subtropical
characteristics by Saturday night and early Sunday. By early next
week, environmental conditions should become unfavorable for any
further development. The low is forecast to begin moving slowly
toward the west-northwest tonight and then northwest on Saturday,
bringing the system closer to the coasts of the Carolinas. A
surface trough extending from the low center to central Florida is
producing scattered to numerous showers and thunderstorms. This
convective activity will spread across South Florida and the NW
Bahamas on Sat.

$$

Chan
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