[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 090553
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Mon Nov 9 2020

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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0500 UTC.

...SPECIAL FEATURES...

Tropical Storm Eta made landfall in the Florida Keys, near 24.9N
80.7W as of 09/0400 UTC. Eta is moving to the WNW at 12 kt.
Estimated minimum central pressure is 991 mb. Maximum sustained
wind speed is 55 kt with gusts to 65 kt. Most of the convection in
the SW quadrant has been eroded due to dry air in the upper
levels mixing in and around the entire circulation. Scattered
moderate to isolated strong convection is within 270 nm north of
the center, including over southern and central Florida. Isolated
moderate convection is within 90 nm SE quadrant. Sustained
tropical storm force winds have been reported along portions of
the southeast Florida coast and Upper Florida Keys during the past
several hours. Seas of 12 ft or greater are within 60 nm of the
center except 30 nm NW quadrant with peak seas to 25 ft. On the
forecast track, the center of Eta will pass near or over the
Florida Keys this morning, and be over the southeastern Gulf of
Mexico late today and Tuesday. Some strengthening is forecast
during the next day or so and Eta is forecast to become a
hurricane when it moves over the southeastern Gulf of Mexico.
Heavy rainfall today over South Florida and the Bahamas could lead
to additional flooding. Please read the latest NHC Public
Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and
Forecast/ Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details.

West Atlantic Gale Warning: The pressure gradient between Eta and
high pressure over the Mid-Atlantic states is resulting in a
large area of strong to near gale force easterly winds across the
western Atlantic, west of 67W. Within this area, gale force winds
are currently occurring west of 76W and south of 30N, according to
a recent ASCAT pass. The gale warning will remain in effect for
this area through this evening, before winds diminish below gale
force tonight. Seas to 20 ft are expected in the area this morning.
Please read the latest NHC High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

North Central Atlantic Gale Warning: A 1010 mb low is currently
near 28N46W and is producing winds of 20-25 kt from 26N-31N
between 41W-48W. Shower and thunderstorm activity is beginning to
show some signs of organization. Scattered moderate to isolated
strong convection is from 25N-32N between 36W-47W. The low has a
medium chance of developing into a tropical or subtropical cyclone
during the next 48 hours while the system moves eastward.
Regardless of whether it becomes tropical, the low is forecast to
produce gale force winds Tuesday morning north of 26N and east of
42W. Winds will diminish to below gale force on Wed as the low
moves east of 35W. Seas of 12-17 ft are expected Tue through Wed
north of 26N between 32W-42W. See the latest NHC High Seas
Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more
details.

...TROPICAL WAVES...

A tropical wave is entering the eastern Caribbean with axis along
61/62W from 05N-19N, moving W at 10 kt. A surface trough is
associated with this tropical wave, as noted in a recent ASCAT
pass. Fresh SE winds are east of the wave axis. Scattered moderate
to isolated strong convection is along and within 360 nm east of
the wave axis from 12N-18N. Expect enhanced rainfall this morning
over portions of the Windward and Leeward Islands. This tropical
wave is forecast to move over the central Caribbean Sea, where an
area of low pressure could form in a couple of days. Environmental
conditions are forecast to be conducive for development, and a
tropical depression could form late this week or over the weekend
while the system moves slowly westward.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of West Africa near
11N15W to 08N18W. The ITCZ continues from 08N18W to 05N23W to
04N38W to 05N50W. Scattered moderate convection is from 02N-12N
between 23W-46W.

GULF OF MEXICO...

Tropical Storm Eta is centered over the Middle Florida Keys as of
09/0400 UTC. A large upper-level low centered over T.S. Eta is
aiding in wrapping dry air into the circulation from the southwest
quadrant. Scattered showers associated with Eta cover the SE
Gulf, east of 84W from 22N-29N. Fresh to strong NE winds are over
the eastern Gulf, east of 88W, with tropical storm force winds
near the Florida Keys. Seas over 8 ft are occurring east of 88W
from 22N-28N, with much higher seas near Eta. For more details on
Eta, please see the Special Features section above.

West of 90W, mainly gentle wind speeds prevail. The NW Gulf has
seas of 4 to 6 ft, while the SW Gulf is experiencing 2 to 4 ft
seas. No significant precipitation is seen west of 85W.

Tropical Storm Eta will move to near 24N84W this evening,
strengthen to a hurricane near 23.5N85W Tue morning, and weaken
to a tropical storm near 26.5N84.5W Wed evening. Eta will
gradually weaken as it moves to near 28N84W late Thu. A cold
front will move into the NW Gulf Wed and become stationary over
the northern Gulf through Fri.

CARIBBEAN SEA...

Tropical Storm Eta is centered over the Middle Florida Keys. A
large upper-level low centered over T.S. Eta extends upper-level
troughing over the NW Caribbean. An upper-level ridge covers the
remainder of the Caribbean. Due to the positioning of these
upper-level features, strong upper-level diffluence and
divergence are occurring over the southeast Bahamas, Hispaniola
and Puerto Rico. As a result, scattered moderate to isolated
strong convection is seen from 15.5N-21N between the British
Virgin Islands and the eastern Dominican Republic, including near
and over Puerto Rico. Scattered moderate convection is also seen
east and south of Jamaica from 14N-19N between 75W-78W. Scattered
moderate convection is over northern Nicaragua and southern
Honduras due to the east Pacific monsoon trough. A tropical wave
along 61/62W is producing convection over the Lesser Antilles. See
the Tropical Waves section above for details. A recent ASCAT pass
shows fresh to locally strong S winds from Jamaica to the
Windward Passage and in the Mona Passage. Fresh W winds are over
portions of the NW Caribbean, north of 16N and west of 80W. Gentle
to moderate winds are seen elsewhere.

Tropical Storm Eta will strengthen to a hurricane near 23.5N85W
Tue morning before turning N and weakening to a tropical storm
near 26.5N84.5W Wed evening. Expect seas in excess of 12 ft to
reach the Yucatan Channel tonight, with N swell spreading through
the western Caribbean Tue. Seas in the NW Caribbean will then
gradually subside Wed. A tropical wave, currently moving through
the Windward Islands, will reach the central Caribbean in a few
days, where an area of low pressure could form. There is a medium
chance of tropical cyclone formation within the next 5 days while
the system moves slowly westward.

ATLANTIC OCEAN...

Tropical Storm Eta is centered over the Middle Florida Keys as of
09/0400 UTC. Scattered moderate to isolated strong convection
directly associated with Eta extends between the NW Bahamas and
South Florida. Scattered moderate convection also extends offshore
central and northern Florida. Although the tropical storm force
winds associated with Eta extend to 27N west of 78W, gale force E
winds of 35 kt due to a tight pressure gradient extend northward
from 27N-30N between 76W-81W. Strong winds are elsewhere from
23N-32N between 67W-82W. Of note, an area of strong upper-level
diffluence is enhancing scattered moderate to isolated strong
convection between the British Virgin Islands and the southeast
Bahamas, from 18N-24N between 62W-74W. Additional scattered
moderate convection is seen from 24N-31N, between 69W-77W. Please
see the Special Features section above for more details on
Tropical Storm Eta and the Gale Warning to the east of central
and northern Florida.

Farther east, a 1010 mb low near 28N46W is the subject of a Gale
Warning and is also being discussed in the NHC Tropical Weather
Outlook, with a medium chance of tropical cyclone formation within
48 hours. See the Special Features section above for details. A
1026 mb high is centered near 33N24W.

Tropical Storm Eta will move to near 23.5N85W by Tue morning, and
25.5N85W Wed morning. Tropical storm force winds will continue
east of the Florida Keys and Miami this morning. Gales due to a
tight pressure gradient will persist north of the NW Bahamas and
east of Florida through this evening. Large seas are expected in
the western Atlantic through Tue before gradually subsiding
through late Thu night.

$$
Hagen
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