[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 081055
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Fri Oct 8 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.

...TROPICAL WAVES...

An Atlantic tropical wave is near 36W/37W from 16N southward,
moving W at 15 to 20 kt. Scattered moderate to isolated strong
convection is seen from 03N to 10N between 30W to 40W.

Another tropical wave is over the eastern Caribbean along 64W,
moving W at 15 to 20 kt. Scattered showers and thunderstorms are
noted on either side of the wave axis from 13N to 17N between 62W
and 70W. Similar convective activity is affecting the Windward
Islands, and the waters E of Barbados. Recent scatterometer data
provide observations of fresh to strong winds in the wake of the
wave axis, including the Atlantic waters E of the Lesser Antilles
and mainly S of Guadeloupe.

A tropical wave is near 92W and extends from the E Bay of Campeche
southward across SE Mexico into the E Pacific Ocean, moving W at
10 to 15 kt. A cluster of moderate to isolated strong convection
is over the E Bay of Campeche, including the Mexican coast.

...MONSOON TROUGH/ITCZ...

The monsoon trough remains over Africa while the ITCZ extends
westward from the Sierra Leone coastline at 08N13W to 06N25W to
07N35W to 08N45W. Scattered moderate to isolated strong convection
is from 04N to 09N between 14W and 27W.

...GULF OF MEXICO...

A stationary front is over the western Florida Panhandle and extends
southwestward to near 28N88W. Scattered showers and isolated
thunderstorms are ahead of the front near the Florida Big Bend
area. A surface trough stretches from 28N88W to 22N92W while the
northern extent of a tropical wave is over the eastern Bay of
Campeche generating scattered showers and thunderstorms. Recent
scatterometer data show fresh to strong northerly winds between
the tropical wave and the coast of Mexico, including the Veracruz
region. Moderate to fresh E winds dominate the Straits of Florida
with gentle to moderate NE to E winds blowing across the remainder
of the Gulf waters. A pair of altimeter passes indicate seas of 2
to 4 ft across the Gulf region.

For the forecast, the pressure gradient between high pressure
along eastern slopes of the Sierra Madre Mountains in Mexico and
the northern extent of a tropical wave over the eastern Bay of
Campeche will support moderate to locally fresh northerly winds
over the Veracruz adjacent waters through early this evening. Weak
high pressure will build across the E half of the Gulf this upcoming
weekend into early next week, and support moderate to locally fresh
return flow W of 90W Sun through Tue night.

...CARIBBEAN SEA...

The most recent scatterometer data indicate the presence of fresh
to strong trade winds over the south-central Caribbean, including
the Gulf of Venezuela. Fresh to strong NE winds are also noted
across the Windward passage. A tropical wave is over the eastern
Caribbean with axis along 64W. Fresh to strong easterly winds
follow the wave. Please, see the Tropical Wave section for more
details. Elsewhere gentle to moderate winds prevail. Seas are 6-8
ft across the south-central Caribbean, 5-6 ft E of 64W, and 3-5
ft elsewhere. Outside of the convective activity associated with
the tropical wave, isolated showers and thunderstorms are noted
over the NW Caribbean.

For the forecast, moderate to locally fresh trades are expected
across the south-central Caribbean most of the forecast period as
a weak ridge persist N of the Caribbean Sea. The tropical wave
along 64W is forecast to reach the central Caribbean on Sat. A low
level disturbance, currently located along 51W/52W, is accompanied
by fresh to strong winds and active weather. It is forecast to
reach the Windward Islands on Sat, and move across the eastern
Caribbean Sun into Mon.

...ATLANTIC OCEAN...

An elongated area of low pressure located N of area and more than
100 miles off the coast of South Carolina is producing disorganized
showers and thunderstorms well to the east of its center of circulation.
Strong upper-level winds should prevent any significant tropical
or subtropical development during the next few days. By late this
weekend, the low is expected to interact with a frontal boundary
located to its north, which should end the opportunity for tropical
or subtropical formation. Regardless of development, the low is
forecast to move slowly east-northeastward at about 5 mph, and it
could bring gusty winds and locally heavy rain to eastern portions
of the Carolinas through the weekend.

A stationary front enters the forecast region near 31N30W and
continues SW to near 28N45W. Scattered showers and thunderstorms
are along the front/trough between 42W and 60W. Light to gentle
winds and seas of 5-7 ft are near these features. Moderate to
fresh easterly winds are between the SE Bahamas and Cuba, with
fresh to strong winds near the approach to the Windward passage.
Similar wind speeds are related to the low level disturbance
located near 51W/52W, and N of the Cabo Verde Islands. Moderate to
fresh trades dominate roughly the waters from 10N to 20N between
the W coast of Africa and the Lesser Antilles. Farther E, high
pressure of 1021 mb located near 32N23W dominates the eastern
Atlantic. An upper-level low situated just NE of the Cabo Verde
Islands near 20N22W is generating some shower activity.

The Cumbre Vieja volcano, that is on the island of La Palma in
the Canary Islands, has been erupting since 19 September at 1410
UTC. An ash plume is partially identifiable on satellite imagery
drifting westward toward the Tenerife Island. Top is estimated
with Webcams at 11,000 ft. 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/. The next advisory
will be issued no later than 08/1500 UTC.

For the forecast W of 65W, An elongated area of low pressure located
N of area and more than 100 miles off the coast of South Carolina
is producing disorganized showers and thunderstorms well to the
east of its center of circulation. Strong upper-level winds should
prevent any significant tropical or subtropical development
during the next few days. By late this weekend, the low is
expected to interact with a frontal boundary located to its north,
which should end the opportunity for tropical or subtropical
formation. The frontal boundary is forecast to move slowly across
the NW Bahamas and south Florida during the upcoming weekend.

$$
GR
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