[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 012124
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat Oct 2 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

Hurricane Sam is centered near 30.0N 61.8W at 2100 UTC or 210 nm
SE of Bermuda moving N at 17 kt. Estimated minimum central
pressure is 937 mb. Maximum sustained wind speed is 130 kt with
gusts to 160 kt. Numerous moderate to strong convection extends
outward from the center 180 NM in the N semicircle and 90 NM in
the S semicircle. Scattered moderate convection exists elsewhere
within 300 nm N quadrant. Maximum significant wave height near
the center is estimated at 43 ft with 12 ft seas extending outward
as much as 270 NM from the center. Sam is expected to turn NE at a
slightly slower forward speed this weekend. Slow weakening is
anticipated over the next several days as it moves over
progressively cooler waters and into an environment with more
unfavorable wind shear. However, Sam is expected to remain a major
hurricane through Saturday night. Early next week, Sam may begin
to transition to a strong extratropical storm. Please read the
latest High Seas Forecast issued by the National Hurricane Center
at 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.

Tropical Storm Victor is centered near 12.0N 34.3W at 01/2100
UTC or 650 nm WSW of the Cabo Verde Islands moving WNW at 11 kt.
Estimated minimum central pressure is 997 mb. Maximum sustained
wind speed is 55 kt with gusts to 65 kt. Numerous moderate to
strong convection is noted within 120 NM of the center. Scattered
moderate convection is located elsewhere within 240 NM NE
quadrant. Maximum significant wave height near the center is
estimated to be near 19 ft and the seas should gradually diminish
during the next couple days. Victor is forecast to turn NW Sat,
then continue moving NW through early next week. The tropical
storm is expected to weaken over the next several days due to very
unfavorable environmental conditions. Please read the latest High
Seas Forecasts issued by Meteo-France at website
http://weather.gmdss.org/II.html and by the National Hurricane
Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml as
well as the latest NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

A tropical wave axis extends along 56W from 05N to 17N, moving W
at 10 to 15 kt. Scattered moderate convection is noted from 08N to
10N between 48W and 57W.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends from the coast of Liberia near 04N09W to
05N19W. The ITCZ then extends from 05N19W to 05N25W. The ITCZ
resumes to the west of Tropical Storm Victor near 07N37W and
continues to 06N47W. Aside from convection associated with Victor
and the tropical wave, described in the sections above, scattered
moderate to isolated strong convection extends from 01N to 08N
between 10W and 23W. Scattered moderate convection is noted from
06N to 09N between 42W and 50W.

GULF OF MEXICO...

Surface ridging N of the Gulf of Mexico is prompting mainly
moderate or weaker SE winds across most of the basin, but some
fresh NE winds are occurring in association with a weak diurnal
trough over the Yucatan Peninsula. Also, with high pressure
building S into the SW Atlantic, the pressure gradient has
increased over the SE Gulf and fresh E winds are also occurring in
the Florida Straits, N of Cuba, and adjacent sections of the Gulf.
Seas are 2 to 4 ft. Scattered moderate to isolated strong
convection within 90 nm of the Texas coast is associated with a
warm front retreating away from the Gulf, through Texas.

For the forecast, the weak ridge of high pressure will persist
north of the Gulf through tonight, supporting tranquil conditions.
Stronger higher pressure will build across the region by Sun,
allowing winds and seas to increase over the SE Gulf over the
weekend. A weak cold front should move across the Gulf on Mon and
Tue, with little enhancement of the winds and seas.

CARIBBEAN SEA...

A fairly modest pressure gradient is supporting mainly moderate
trades over the basin today, with seas of 2 to 4 ft. The eastern
N Pacific monsoon trough extends along 10N into the SW Caribbean,
and is inducing scattered moderate convection along and S of 11N.
Also, an upper level disturbance is assisting in the development
of scattered moderate to isolated strong convection over the
eastern basin, from 13N to 17N between 62W and 70W. Diurnal
heading has spawned convection over mainly the land masses of the
Greater Antilles and Venezuela, but some of this activity is
impact waters within 60 miles of the coasts.

For the forecast, high pressure will build north of the area this
weekend. This will bring an increase in trade-winds and seas
across the central and E Caribbean as well as the tropical N
Atlantic this weekend through the middle of next week.

ATLANTIC OCEAN...

Refer to the Special Features section above for details on
Major Hurricane Sam and Tropical Storm Victor.

The Cumbre Vieja volcano on the island of La Palma in the Canary
Islands near 28.6N 17.8W has been erupting since September 19th.
High concentration of volcanic ash is found near the volcano.
Marine and aviation interests should monitor this ongoing
situation by reading the latest Volcanic Ash Advisory issued by
Meteo-France at http://vaac.meteo.fr/volcanoes/la-palma/ for
details.

Aside from Hurricane Sam and Tropical Storm Victor, the tropical
N Atlantic is dominated by ridging from a double-barreled high
pressure of 1031 mb over the Azores and 1030 mb centered near
37N38W. Moderate to fresh NE to E trades encompass the basin south
of this ridging. Seas outside of tropical cyclones are generally
6 to 9 ft. A previous cold front in the SW Atlantic has devolved
into a low pressure trough, that stretches this evening from
30N66W to 27N75W. Winds and seas on both sides of this trough are
moderate and 5 to 7 ft, respectively.

For the forecast west of 55W, Swells generated from Major
Hurricane Sam, centered E of the area, will impact waters northeast
of the Bahamas through the weekend. High pressure will build in
to the area in the wake of Sam, which will bring continued moderate
to occasionally fresh winds through Tue.

$$
KONARIK
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