[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 130918
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Fri Nov 13 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 0600 UTC surface analysis and satellite imagery through
0800 UTC.

...SPECIAL FEATURES...

Post-Tropical Cyclone Eta is centered near 33.3N 76.8W at 13/0900
UTC or 70 nm SE of Wilmington North Carolina moving ENE at 18 kt.
Estimated minimum central pressure is 1004 mb. Maximum sustained
wind speed is 40 kt with gusts to 50 kt. Post-Tropical Eta has
scattered moderate to strong convection noted from 32.5N-36N and
west of 71W to just offshore of the Outer Banks of North Carolina.
Eta extends a trailing trough to near South Florida with
scattered showers and isolated thunderstorms within 60-75 nm ahead
of it, as well as fresh to strong winds and seas of 8-11 ft.
Post-Tropical Eta will continue to move away from the area,
dissipating completely by late Sat night.
Please read the final 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.

Tropical Storm Theta is centered near 31.9N 24.9W at 13/0900 UTC
or 390 nm SSE of the Azores moving E at 10 kt. Estimated minimum
central pressure is 993 mb. Maximum sustained wind speed is 50 kt
with gusts to 60 kt. Scattered moderate to strong convection is
noted within 180 nm in the NE quadrant and between 60 nm and 180
nm in the SW quadrant of Theta. Theta is forecast to gradually
weaken through Sat night, becoming a post-tropical remnant low by
Sun afternoon, and dissipating by Tue night.
Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more
details.

Low pressure of 1009 mb is centered in the central Caribbean Sea
near 15N73W along a tropical wave. Convection has increased and
become a little better organized overnight with scattered moderate
to strong from 13N-16N between 67W-75W. Additional development is
expected, and a tropical depression will likely form within the
next day or two as it moves slowly westward over the central and
western Caribbean Sea. Interests in Honduras and Nicaragua should
closely monitor the progress of this system. Winds associated with
this low are forecast to reach gale force/tropical storm force by
36 hours, thus a gale warning has been issued due to high
confidence in these conditions. Regardless of tropical
development, this disturbance is expected to bring heavy rainfall
along with possible flash flooding to portions of Hispaniola over
the next day or so. For more detailed information refer to
products issued by your local weather office.
Please read the latest NHC Atlantic Tropical Weather Outlook at
https://www.nhc.noaa.gov/text/MIATWOAT.shtml for more details.

...TROPICAL WAVES...

A tropical wave axis is along 57W from 17N southward, moving W at
10-15 kt. Scattered moderate and isolated strong convection is
noted from 13N-15N between 50W-57W, along with scattered moderate
convection from 11N-12N between 55W-58W.

A tropical wave axis is along 74W. Please read the Special
Features section above for more details on this tropical wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough is inland in Africa. The ITCZ axis extends
from the coast of Africa near 13N17W to 08N30W to 03N47W.
Scattered moderate and isolated strong convection is noted from
01N-08N between 17W-26W, from 10N-11N between 30W-34W, and from
01N-07N between 35W-43W.

GULF OF MEXICO...

High pressure is north of the area over the lower Mississippi
Valley with a ridge axis extending SW to the western Gulf of
Mexico. Overnight scatterometer data showed mainly moderate
anticyclonic flow across the basin. Seas are mainly 3-5 ft per
recent buoy and ship observations.

High pres will be N of the area through Sun, gradually shifting
NE-E. A cold front will move into the northern Gulf Sun, and
reach the central Gulf by late Mon, pushing SE of the basin late
Tue night. Winds will becoming NE at moderate to fresh speeds
behind the front, except fresh to strong NW winds offshore of
Veracruz. Winds will increase to fresh to strong across the basin
Tue and Tue night, except in the NW Gulf, due to a tightening
pressure gradient.

CARIBBEAN SEA...

Please see the Special Features section above for details on a
tropical wave and developing low pressure area in the central
Caribbean Sea.

Otherwise, high pressure is northeast of the basin. This high
combined with the area of low pressure is supporting fresh to
strong winds south of Haiti per overnight scatterometer data.
Gentle to moderate winds along with seas of mainly 3 ft or less
prevail across the western Caribbean Sea, with moderate to fresh
trades and seas of 4-6 ft in the eastern Caribbean Sea.

Conditions will improve in the central Caribbean as the area of
low pressure shifts W-NW with mainly moderate to locally fresh
trades prevailing across the central and eastern Caribbean in its
wake through early next week.

ATLANTIC OCEAN...

Please see the Special Features section above for details on
Tropical Storm Eta and Tropical Storm Theta.

Otherwise, high pressure is over the central Atlantic with a ridge
axis stretching W-SW to across the Central Bahamas. Fresh to
strong winds were noted by overnight scatterometer data north of
Hispaniola due to a tight pressure gradient, with moderate to
fresh trades elsewhere. Combined seas of 6-8 ft dominate the
waters W of 60W and E of the Bahamas, with seas of 8-11 ft east
of 60W in mixed easterly swell, some generated by Theta.

Eta will continue to move NE away from the area overnight. Fresh
to strong SE winds and associated seas will decrease through Fri
as Eta moves northeastward. Eta will drag a trailing trough across
the basin through the weekend. A cold front will move off the SE
U.S. coast Mon, shifting SE through Tue night. Winds will increase
to fresh to strong behind the front by Tue night as the pressure
gradient tightens.

$$
Lewitsky
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