[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091017
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 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 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...SPECIAL FEATURES...

An area of low pressure located about 200 miles south-southeast 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 through early Sunday. However, by late Sunday and
Monday, environmental conditions should become unfavorable for any
further development. The low is forecast to move slowly northwestward
during the next day or so near the North Carolina coast.

Regardless of development, intermittent periods of locally heavy
rains and gusty winds will affect eastern portions of North Carolina
during the next day or two. An Air Force Reserve reconnaissance
aircraft is scheduled to investigate the system this afternoon, if
necessary. 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
latest High Seas Forecast from the Ocean Prediction Center at
https://ocean.weather.gov for more information.

...TROPICAL WAVES...

An Atlantic tropical wave is near 44W from 16N southward, moving
W at 15 to 20 kt. Scattered moderate convection is where the wave
meets the ITCZ from 06N to 09N between 41W and 47W.

A second tropical wave is E of the Lesser Antilles along 55W/56W
from 18N southwestward, moving W near 10 kt. A cluster of moderate
to isolated strong convection is along the wave axis covering the
waters from 11N to 14N between 54W and 57W. The wave will bring
showery and windy conditions to the Windward Islands later today,
then the Leeward Islands tonight; and the US/UK Virgin Islands and
Puerto Rico late on Sun. It might reach Hispaniola on Mon.

A Caribbean tropical wave is near 71W and extends from Dominican
Republic southward across western Venezuela, moving W near 15 kt.
Convection is limited along the wave axis, with the exception of
moderate to isolated strong convection over Lake Maracaibo.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic Ocean through the coast of
Senegal near 15N17W, then continues SW to near 07N25W. The ITCZ
extends from 07N25W to 08N38W to 06N49W. Scattered moderate to
isolated strong convection is found from 07N to 11N between 20W
and 30W, and from 03N to 10N between 30W and 40W.

...GULF OF MEXICO...

A frontal trough extends from Ft. Myers, Florida to near 22N90W.
Scattered showers and thunderstorms are along the frontal trough
affecting South Florida and the SE Gulf waters. The remainder of
the Gulf is under the influence of a ridge. A cluster of moderate
to strong convection is over the eastern Bay of Campeche, just
ahead of a surface trough extending over the Yucatan Peninsula.
Recent satellite derived wind data show mainly gentle to moderate
winds across the basin, with the exception of moderate to fresh
northerly winds over the Bay of Campeche. Seas are generally in
the 1 to 3 ft range.

For the forecast, the above mentioned frontal trough will move
slowly across South Florida and the Florida Keys this weekend
helping to induce scattered to numerous showers and thunderstorms.
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...

A tropical wave is currently located E of the Lesser Antilles
producing active weather and fresh to strong winds. Refer to the
Tropical Waves section for more information. Otherwise, gentle to
moderate trade winds prevail, with the exception of light to gentle
winds over the NW Caribbean. Seas are 3 to 5 ft across most of the
waters S of 18N E of 83W, and 1 to 3 ft over the NW Caribbean.
Seas of 7-9 ft are noted in association with the tropical wave.

For the forecast, the tropical wave currently located E of the
Lesser Antilles along 55W/56W will bring showery and windy
conditions to the Windward Islands later today, then the Leeward
Islands tonight; and the US/UK Virgin Islands and Puerto Rico late
on Sun. It might reach Hispaniola on Mon. Seas of 7-9 ft will
follow the wave axis over the Atlantic waters through early Mon.

...ATLANTIC OCEAN...

An area of low pressure remains N of area about 200 miles south-
southeast of Cape Hatteras, North Carolina. Please, see the
Special Features section for more details. 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 today
and Sun.

Weak surface troughing is causing scattered showers and isolated
thunderstorms across the west-central Atlantic from 25N to 31N
between 40W and 65W. The trough extends from 31N43W to 29N50W to
28N60W. Moderate to fresh SW to W winds are noted just S of the
trough between 45W and 50W while mainly light to gentle winds
prevail elsewhere near the trough axis. The remainder of the
Atlantic forecast waters is under the influence of a ridge
anchored on a 1029 mb high pressure located over the Azores. The
pressure gradient between the ridge and lower pressures over W
Africa is resulting in an area of fresh to strong NE winds from
20N to 25N E of 26W to the coast of Western Sahara.

A northerly swell event will begin to propagate across the central
Atlantic waters by Sun evening, building seas to 8 to 11 ft N of
a line from 31N38W to 28N50W to 31N62W by early Mon morning. This
swell event will cover most of the waters N of 24N E of 60W by Mon
evening.

The Cumbre Vieja volcano, that is on the island of La Palma in
the Canary Islands, has been erupting since 19 September 2021.
Currently, volcanic ash is not easily detectable due to cloud
cover. 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/.

$$
GR
This weather bulletin was brought to you by:
www.nashvilleweather.net