AXNT20 KNHC 241029
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun Oct 24 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
An Atlantic tropical wave is near 18W from 16N southward, moving
W at around 10 to 15 kt. Scattered moderate convection is present
E of 20W to the coast of Africa.
An Atlantic tropical wave is near 56W from 16N southward to
Guayana, moving W around 15 kt. Associated convection is noted
south of 12N between 50W to 60W.
A Caribbean tropical wave is along 70W from Hispaniola to W
Venezuela, moving W near 15 kt. Subsidence and drier air aloft is
hindering any significant convection near this wave axis.
Another Caribbean tropical wave is near 84W south of 20N, moving
W around 20 kt. Scattered showers and thunderstorms are noted in
the vicinity of the wave axis.
A monsoon trough exits through the African coast near Guinea
near 13N16W to 06N24W. The ITCZ then continues from 06N24W to
02N40W. Scattered moderate convection is found near the monsoon
trough from 06N to 12N between 20W to 24W. Scattered showers and
isolated thunderstorms are evident about 180 nm north of the
...GULF OF MEXICO...
A 1010 mb low pressure near 20N94W has a surface trough extending
NW to near Tampico, Mexico. Significant upper-level moisture and
synoptic scale lift is leading to disorganized scattered convection
over a broad area of the Gulf. Gentle to moderate winds and seas
of 2 to 4 ft are found across much of the Gulf, except locally
fresh winds with seas up to 6 ft near in the NW Gulf.
For the forecast, gentle to moderate winds will prevail across
the basin and become light to gentle through Tuesday. A strong
cold front is expected to move off the Texas coast on Wednesday
and move across the basin through Thu. Expect fresh to strong
winds and rough seas across the northern and central Gulf later in
Refer to the Tropical Waves section for details on convection
across the Caribbean Basin. Otherwise moderate to fresh trades
dominate the central and eastern basin, with gentle to moderate
winds in the west. Some locally strong winds are occurring
offshore the South American coast. Seas are 5 to 7 ft in the
central and eastern basin, and 2 to 4 ft in the west. Scattered
moderate isolated strong convection is present in the SW Caribbean
associated to the Pac monsoon trough extending from northern
Colombia west across Costa Rica.
For the forecast, high pressure N of the area will support fresh
to locally strong trades E of the Windward Islands and across the
eastern Caribbean through Mon night. Winds are also expected to
pulse fresh to strong in the Venezuela basin tonight through Mon
evening. By Tue and Wed, gentle to moderate tradewinds are expect
to prevail across the basin.
A surface trough curves southwestward from SW of Bermuda across
the NW Bahamas. Scattered moderate convection is noted S of 30N
and W of 72W. Two surface trough are analyzed east of the trough
in the Bahamas. Trough to the north is located near 31N68W to
30N71W. Further south, the second trough is analyzed from 26N68W
to 26N72W. Refer to the Tropical Waves and Monsoon Trough/ITCZ
sections above for additional convection across the Atlantic
Moderate trades and seas of 5 to 8 ft are present N of 16N between
the NW African coast and 60W. W of 71W, gentle to moderate S to
SW winds and seas at 3 to 5 ft are seen from the Greater Antilles
northward to 31N. Moderate to fresh NE trades and seas of 8 to 10
ft are found from 05N to 16N between 36W and the Lesser Antilles.
Gentle to moderate with locally fresh winds and seas at 5 to 7 ft
prevail for the rest of the basin.
The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Continues ash
emission is noted with small column height. Medium to high
volcanic ash concentration 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/.
For the forecast W of 65W, a trough extending across the northern
Bahamas and off the southeast Florida coast will continue to
support scattered moderate convection across the region today. A
weak boundary the Atlantic waters will slowly meander southward
and dissipate today. This will enhance additional convection
through early in the week. Moderate to locally fresh winds will
develop off the Florida coast on Sun into Mon near the old