[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271707
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Wed Oct 27 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 1200 UTC surface analysis and satellite imagery through
1705 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: Strong to gale force winds will
follow a cold front expected to move through the Gulf of Mexico
today through Thu night. A gale warning for frequent gusts to
gale force has been issued for this area valid from Wed night
through Fri. Seas will build as high as 20 ft in the wake of the
front over the northern Gulf. Mariners are urged to heed caution
as a robust line of showers and thunderstorms will race ahead of
the front, producing strong gusty winds, heavy rain and reduced
visibility. Please, see the latest NWS High Seas Forecast issued
by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further details.

...TROPICAL WAVES...

The axis of a tropical wave is along 33W, south of 20N, and it is
moving W at 10-15 kt. A few showers are noted near the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends off the southern coast of Senegal near
14N17W to 07N27W and to 07N38W. The ITCZ extends from 07N38W to
08N50W and to NE Venezuelan coast near 10N61W. Scattered moderate
convection is observed within 250 nm on both sides on the monsoon
trough and ITCZ between 47W and the coast of Africa. Scattered
moderate convection is also present within 250 nm of the ITCZ
between 57W and 64W.

GULF OF MEXICO...

The main feature of interest in the Gulf of Mexico is the
aforementioned cold front approaching the NW portion of the
basin. For more details, please see the Special Features section.

As of 1500 UTC, a robust squall line is entering the NW Gulf and
an outflow boundary is racing ahead of it. Surface observations
indicate that fresh to strong S winds have developed in the NW
Gulf ahead of the cold front. Strong wind gusts, heavy rain and
reduced visibility can be expected as the squall line races
eastward over the N Gulf. Elsewhere, a stationary front extends
from SE Louisiana to SW Florida and it is producing a few
isolated showers. The rest of the Gulf enjoys fairly tranquil
weather conditions. Outside of the influence of the strong cold
front nearing the NW Gulf, moderate or weaker winds are found in
the remainder of the basin. Seas of 3-5 ft are noted W of 95W and
1-3 ft elsewhere in the Gulf.

For the forecast, the previously mentioned cold front will move
off the Texas coast today. This front will then move quickly
across the Gulf, accompanied by a band of showers and
thunderstorms, some strong, through Thu night. Fresh to strong S
winds will continue ahead of the front, with strong to gale force
winds developing the portions of the north-central and NE Gulf
late tonight into Fri.

CARIBBEAN SEA...

The interaction of a weak surface trough in the central Caribbean
Sea and a weak 1010 mb low pressure along the E Pacific monsoon
trough results in an area of showers and isolated thunderstorms
from the NW coast of Colombia to 14N and between 76W and 79W. The
rest of the basin is under the influence of a dry airmass,
supporting fairly tranquil weather conditions. A recent
scatterometer satellite pass indicate fresh to locally strong
trades S of 15N and E of 77W. Fresh trades are also noted in the
Gulf of Honduras, while moderate or weaker trades are present
elsewhere in the basin. Seas of 4-7 ft are prevalent in the
central, SW and E Caribbean, while 2-4 ft are found in the rest of
the region.

For the forecast, a weak ridge over the northern Caribbean Sea
will support mainly fresh trades across the south-central
Caribbean, including the Gulf of Venezuela through early Thu.
Gentle to moderate SE to S winds will prevail over the NW
Caribbean through Thu night ahead of a cold front forecast to
reach western Cuba and the NW Caribbean. The front will extend
from western Cuba to the Gulf of Honduras by midday Fri, and from
central Cuba to NE Honduras on Sat, then stall on Sun from eastern
Cuba to near Cabo Gracias a Dios, Nicaragua while dissipating.

ATLANTIC OCEAN...

A cold front extends from the strong extratropical cyclone off New
England, entering the tropical Atlantic near 31N66W to 27N71W,
becoming a stationary front and continuing across the NW Bahamas
and South Florida. There is a pre-frontal trough that extends
from 31N63W to the central Bahamas. Scattered showers to isolated
thunderstorms are found N of 25N and between 61W to 75W. Recent
scatterometer satellite data show fresh to strong cyclonic winds N
of 25N and between 57W and 75W. Seas of 7-10 ft are occurring N
of 28N and between 60W and 77W.

Elsewhere, a couple of weak troughs are found in the central
Atlantic, but no significant convection is associated with these
features. The central and eastern tropical Atlantic are dominated
by a broad 1023 mb high pressure between the Azores and Madeira
Islands, supporting fairly tranquil weather conditions and
moderate to locally fresh winds. Seas 4-7 ft are noted across most
areas in the basin.

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. 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 west of 65W, a cold front from near Bermuda to
around West Palm Beach, Florida, is beginning to stall, and will
dissipate tonight. and early Thu. N of 25N and E of 75W, fresh to
strong W winds follow this boundary, along with seas of 8 to 10
ft. The next cold front from will sweep through Thu night through
Fri night, then stall from 31N68W to eastern Cuba over the
weekend. Fresh to strong winds and building seas are expected on
either side of this front.

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