[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211027
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sat Oct 21 2023

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
0900 UTC.

...SPECIAL FEATURES...

Hurricane Tammy: Hurricane Tammy is centered near 15.2N 60.4W at
21/0900 UTC or 50 nm ESE of Dominica, moving NW at 8 kt. Estimated
minimum central pressure is 991 mb. Maximum sustained wind speed
is 70 kt with gusts to 85 kt. Hurricane-force winds extend outward
up to 20 nm N of the center, with tropical storm force winds
present up to 110 nm from the center, mainly in the E semicircle.
Seas of 12 ft or greater extend up to 270 nm from the center,
especially in the N semicircle, where peak seas reach 23 ft.
Numerous strong convection is noted with 180 nm of the center,
with scattered moderate to isolated strong convection up to 270 nm
from the center, especially in the E semicircle.

Please, consult bulletins and forecasts from your local weather
office. Read the latest HIGH SEAS FORECAST, that is issued by
the National Hurricane Center, at the website -
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, and the latest
Tammy NHC Forecast/Advisory and Public Advisory, at
www.hurricanes.gov, for more details.

East Atlantic developing gale: The METEO-FRANCE forecasts consist
of gale-force winds for the marine areas IRVING and MADEIRA.
Please, refer to the following website, https://wwmiws.wmo.int,
for details.

...MONSOON TROUGH/ITCZ...

The ITCZ extends from Senegal to 07N29W. A surface trough that
extends from 13N35W to 09N40W disrupts the ITCZ, which reforms
near 08N41W and continues to 05N49W. Numerous moderate to isolated
strong convection extends from the W portion of the ITCZ northward
to around 14N. Scattered moderate convection is noted within about
180 nm N of the surface trough. Scattered moderate convection is
also noted from 03N to 12N between 15W and 34W.

...GULF OF MEXICO...

A surface trough previously in the Bay of Campeche has dissipated,
along with associated convection. Ridging associated with a 1014
surface high centered near 24N94W is dominating conditions in the
basin. This is leading to light to gentle anticyclonic winds, with
seas of less than 2 ft, except 2 to 4 ft in the NE Gulf.

For the forecast, high pressure from central Gulf to Florida will
shift SW today, allowing a weak cold front to sweep through the
NE Gulf today. Another cold front will move through the NE Gulf
Sun through Mon. Looking ahead, high pressure building in the wake
of the front will support moderate to fresh E winds and building
seas Sun night through the middle of next week.

...CARIBBEAN SEA...

Please see Special Features section above for information on
Hurricane Tammy, centered just E of the Dominica and Martinique.

A surface trough extends from Cuba to the far SW Caribbean.
Scattered moderate convection with this trough is present in the
basin W of 75W.

Scattered showers and thunderstorms over the far SW Caribbean, S
and E of the surface trough, are associated with broad low
pressure that may have some slow organization this weekend before
it moves into Central America Mon or Tue. The eastern extension of
the East Pacific monsoon trough also is noted in this region,
along 10W from Colombia to Costa Rica, and is inducing additional
moderate convection.

Away from the influence of Tammy, light to gentle winds prevail,
expect moderate N winds to the W of the aforementioned surface
trough. Seas are mainly 3 ft or less, except in the NE basin were
3 to 5 ft seas dominate.

For the forecast, Hurricane Tammy is near 15.2N 60.4W at 5 AM
EDT, and is moving northwest at 8 kt. Maximum sustained winds are
70 kt with gusts to 85 kt, and the minimum central pressure is 991
mb. Tammy will move to 16.3N 61.3W this afternoon, 17.8N 62.4W
Sun morning, and 19.3N 63.3W Sun afternoon. Hurricane Tammy will
reach 20.6N 64.0W Mon morning, 21.9N 64.2W Mon afternoon, and
22.8N 64.0W Tue morning. Tammy will change little in intensity as
it moves farther N of the Leeward Islands early Wed. Elsewhere, a
trough over the NW Caribbean will dissipate today. A weak cold
front will move into the northwest Caribbean by late Mon.

...ATLANTIC OCEAN...

Please see Special Features section above for details on Hurricane
Tammy, located just E of Dominica and Martinique. Also, see the
Special Features section above for gale conditions being forecast
by METEO-France in the far E Atlantic.

A surface trough extends from 31N70W to central Cuba. Scattered
moderate convection is noted within about 210 nm SE of this
trough. A tight pressure gradient between the low pressure
associated with the surface trough, off the Mid-Atlantic coast of
the U.S. and high pressure over the sub-tropics is leading to
strong to near-gale force SW winds N of 28N and W of 60W. These
winds should continue today then gradually diminish as the low
center moves NE, farther way from the region.

Aside from the hazardous winds being induced by the special
features mentioned above, there are fresh trades in the vicinity
of a surface trough roughly along 40W, described more in the
Monsoon Trough/ITCZ section above. Otherwise, winds are moderate
or less across the basin.

Seas in the area of strong winds in the NW basin are 8 to 11 ft,
otherwise seas are 5 to 7 ft, except for 2 to 4 feet in the
vicinity of and SW of the Bahamas.

A cold front that extends from near 23N40W to Western Sahara is
weakening and associated convection has diminished early this
morning.

For the forecast W of 55W, Hurricane Tammy is near 15.2N 60.4W at
5 AM EDT, and is moving northwest at 8 kt. Maximum sustained
winds are 70 kt with gusts to 85 kt, and the minimum central
pressure is 991 mb. Tammy will move to 16.3N 61.3W this afternoon,
17.8N 62.4W Sun morning, and 19.3N 63.3W Sun afternoon. Hurricane
Tammy will reach 20.6N 64.0W Mon morning, 21.9N 64.2W Mon
afternoon, and 22.8N 64.0W Tue morning. Tammy will change little
in intensity as it moves farther N of the Leeward Islands early
Wed. Farther W, a cold front will move off the NE Florida coast
today and bring strong W winds with it N of 28N. This front will
weaken and stall E of Bermuda early next week. A second cold front
will follow, moving off the northeast Florida coast late Sun,
reach from Bermuda to Fort Lauderdale, Florida, by early Mon.

$$
KONARIK
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