[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041048
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Oct 4 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
0930 UTC.

...SPECIAL FEATURES...

The center of Hurricane Sam is near 40.8N 48.7W at 04/0900Z,
moving NE, or 45 degrees, at 26 knots. The estimated minimum
central pressure is 957 mb. The maximum sustained wind speeds are
90 knots with gusts to 110 knots. Estimated peak wave heights are
to 45 feet. Scattered to numerous moderate to strong convection is
 noted within 210 nm SW and 120 nm NE semicircles. A band of
widely scattered moderate to locally strong convection extends
from the eastern semicircle between 42W and 47W to the SSW to near
27N54W. Large swell continues to be generated by Sam spreading in
all directions, with a new surge of NW to N swell crossing into
the local discussion area as far south as 24N. Please, read the
latest High Seas Forecast issued by the Ocean Prediction Center,
at the website
https://ocean.weather.gov/mobile/mobile_product.php?id=NFDHSFAT1,
and the latest NHC Forecast/Advisory and Public Advisory, at
www.hurricanes.gov, for more details.

The center of Tropical Depression VICTOR is near 18.1N 43.6W at
04/0900Z, moving NW, or 300 degrees, at 12 knots. The estimated
minimum central pressure is 1009 mb. The maximum sustained wind
speeds are 25 knots with gusts to 35 knots. Estimated peak wave
heights are to 12 feet within 150 nm NE of the center. Victor
continues to encounter southerly vertical wind shear. Associated
Scattered moderate isolated strong convection extends from 180 nm
NNE of the center to 30N. The surface circulation of Victor has
begun to open up into an inverted trough, and this will lead to
the system becoming post tropical by this afternoon and to
dissipation Mon night. Please, read the latest High Seas Forecast
issued by the National Hurricane Center at the website,
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, and the latest NHC
Forecast/Advisory and Public Advisory, at www.hurricanes.gov, for
more details.

The OUTLOOK period for the next 24 hours for the METEO-FRANCE
high seas forecast, consists of: the persistence of Northeast
near gale in the area AGADIR. Please, refer to the following
website,
http://weather.gmdss.org/bulletins/METAREA2.HIGH_SEAS_FORECAST.07
39.0407391356168.html, for details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 28W, from 20N
southward, moving W 15 knots. Scattered moderate isolated strong
convection is from 01.5N to 10N between 22W and 41W.

A Caribbean Sea tropical wave is along 73W, from 16N southward,
moving W 10 to 15 knots. An upper level trough across the western
Atlantic Ocean along 76W extends SW across the Bahamas and
central Cuba and into the western Caribbean. This trough is aiding
in producing widespread showers and thunderstorms on either side
of the wave from 14.5N NNE across the Greater Antilles and western
Atlantic between 68W and 75W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of
Gambia near 13N16.5W to 10N19W to 05.5N34W. The ITCZ continues
from 05.5N34W to 07N59W. Isolated moderate convection is from
08.5N to 11N between 48W and 61W.

GULF OF MEXICO...

A weak cold front is along the SE texas coast then extends
westward across the state to far northern Mexico. A weak surface
ridge extends from the western Atlantic along 33W to SE Louisiana
and is producing gentle to moderate NE to E winds across the basin
becoming SE to the west of 94W. Widely scattered clusters of
moderate convection are found along the Mexican nearshore coastal
waters and across NW portions of the Gulf. Seas are 2 to 4 ft east
of 92W and 2 ft or less elsewhere.

The weak cold front will enter the NW Gulf this morning and move
SE through Tue, before stalling across the central Gulf. Gentle to
moderate winds and mild seas will dominate the Gulf during this
period, except for fresh winds and seas 4-5 ft near the coast
across the Veracruz, Mexico area.

CARIBBEAN SEA...

An upper level trough across the western Atlantic Ocean along 76W
extends SW across the Bahamas and central Cuba and into the
western Caribbean to southeast coastal sections of Nicaragua. This
is providing unstable conditions across much of the central
Caribbean, where scattered moderate to strong convection is seen
from the SW Caribbean N-NE to beyond 20N between 68W and 75W.
Small clusters of widely scattered moderate convection is seen
elsewhere across the NW and SE portions of the basin.

The eastern extension of the eastern Pacific Ocean monsoon
trough is along 10N/11N, between 74W in Colombia, beyond Costa
Rica, and into the eastern Pacific Ocean.

Fresh to strong trade winds cover the eastern and central
sections of the Caribbean east of 76W, where seas are 5 to 9 ft.
Generally moderate trade winds are elsewhere. N-NE swell generated
from Sam is moving through the Atlantic passages of the NE
Caribbean.

High pressure offshore of the middle Atlc coast will slide slowly
eastward through Wed. This pattern will produce fresh to strong
trade winds across the NE and central Caribbean through Tue night.
Fresh to strong trade winds will then persist across the central
Caribbean through Thu. Moderate N to NE swell will affect the
tropical Atlc waters and Atlc passages through Wed.

ATLANTIC OCEAN...

An upper level trough along 76W extends SW across the Bahamas and
central Cuba and into the western Caribbean, and is supporting
widespread cloudiness and convection east of the trough to 64W. A
surface trough has developed SE of the upper trough from the
approach to the Windward Passage to 27N71W. Most of the described
convection is occurring along and SE of this trough.

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. 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/.

A broad surface ridge near the Azores covers most of the NE
Atlantic Ocean and extends W-SW to the western Atlantic to the
surface trough. The pressure gradient between the ridge, and
lower pressures in South America result in generally fresh trade
winds from 22N southward between 50W and the Lesser Antilles. A
similar pressure gradient occurs in the NE Atlantic Ocean between
the ridge and lower pressures of NW Africa. Expect fresh to
locally strong NE winds from 20N northward from 28W eastward.
Mainly moderate winds are in the rest of the basin. Wave heights
range from 5 feet to 9 feet, elsewhere in the tropical Atlantic
Ocean, away from Hurricane Sam and Tropical Depression Victor.

Swells generated from Hurricane Sam will prevail across the area
waters today and then continue across the waters E of 70W through
Wed. High pressure along the mid Atlc coast will slide slowly
eastward through mid week. This will produce moderate to fresh
trade winds south of 23N and east of the Bahamas through Tue
before spreading into the southeast Bahamas through Wed night.
Active weather is expected to develop across the waters E of 75W
and NE the Bahamas tonight through Tue as a surface trough
develops across the SE Bahamas and shifts slowly NW.

$$

Stripling
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