[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200532
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Wed Sep 20 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 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

Hurricane Nigel is centered near 33.2N 54.7W at 20/0300 UTC or
510 nm E of Bermuda, moving N at 13 kt. Estimated minimum
central pressure is 971 mb. Maximum sustained wind speed is 85
kt with gusts to 105 kt. Seas are peaking near 35 ft just NE of
the center. The eye of Nigel is surrounded by intense deep
convection from 31N to 33N between 54W and 56W. Hurricane Nigel,
currently a Category Two on the Saffir-Simpson Hurricane Wind
Scale. Nigel is forecast to turn toward the northeast with an
increase in forward speed is expected on Wednesday. Some
additional strengthening is possible through early Wednesday.
Weakening is expected on Thursday and Friday. Nigel is forecast
to become a strong post-tropical cyclone by Friday.
Swells generated by Nigel will affect Bermuda during the next
couple of days. These swells are likely to cause life-threatening
surf and rip current conditions. Please consult products from
your local weather office.

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
Nigel NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

Atlantic Gale Warning: The pressure gradient between low
pressure that is expected to develop along a stationary front
over the northwest part of the SW N Atlantic and high pressure
over the southeastern U.S. is expected to result in gale force
north to northeast winds of 30-35 kt for the waters north of 29N
between 77W-79W on Thursday night. Seas with these winds are
forecast to be 9 to 13 ft. Please see the latest NWS High Seas
Forecast issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2 for further details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis near 28W, south
of 18.5N, moving westward at 10 to 15  kt. Scattered moderate
convection is depicted from 05N to 11.5N and between 28W and
33W.

A western Atlantic tropical wave has its axis near 48W, south of
14N, moving westward at 10 to 15  kt. Scattered moderate
convection is depicted from 07N to 11N and between 46W and 50W.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Senegal near 15N17W and continues southwestward to 09N28W and
then westward to 10.5N46.5W. The ITCZ extends from 10N49W to
11N58.5W. Other than the convection described in the TROPICAL
WAVES section above, scattered moderate to isolated strong
convection is depicted from 11N to 114N, E of 20.5W. Scattered
moderate convection is present from 06N to 13N and between 32W
and 45W and from 10N to 12N between 51W and 56W.

...GULF OF MEXICO...

A stationary front extends from near Fort Myers, Florida,
westward to near 25N89W. Scattered moderate convection is noted
within 90 nm of the boundary. Outside of convection, gentle to
moderate east to southeast winds and seas of 2 to 4 ft are
evident north of the front. Light to gentle winds and seas of 1
to 3 ft are found south of the boundary.

For the forecast, the aforementioned stationary front will
gradually dissipate through early Wed. Otherwise, high pressure
will be in control of the weather regime allowing for generally
gentle to moderate east to southeast winds along with slight
seas, pulsing to moderate to fresh offshore the western Yucatan
Peninsula in the evenings. Developing low pressure east of
Florida will tight the pressure gradient over the NE Gulf
bringing fresh NE winds Thu night into Fri.

...CARIBBEAN SEA...

Divergent flow associated with an upper level trough located in
the NW Caribbean Sea and abundant tropical moisture continue to
support scattered moderate convection in the NW Caribbean. A
weak pressure gradient sustains mainly moderate to fresh
easterly trade winds in the central Caribbean. However, strong
winds are occurring just off the NW Venezuelan coasts. Seas in
the central Caribbean are 4 to 7 ft. Elsewhere, light to gentle
winds and seas of 2 to 4 ft prevail.

For the forecast, long period north to northeast swell will
impact the Caribbean passages and Tropical N Atlantic through
early Wed. Moderate to fresh trades will prevail in the central
Caribbean, locally strong at times offshore northern Colombia
and northwest Venezuela, with moderate or weaker winds elsewhere
through the week.

...ATLANTIC OCEAN...

Please read the SPECIAL FEATURES section for details on
Hurricane Nigel and the ATLANTIC GALE WARNING. In addition read
the TROPICAL WAVES and MONSOON TROUGH/ITCZ sections for
convection in the tropical Atlantic.

A stationary front extending from near 31N70W to Stuart, Florida
is producing scattered moderate to isolated strong convection
within west of 76.5W. Moderate or weaker winds and 2 to 4 ft
seas are found behind the frontal boundary. The remainder of the
Atlantic is dominated by a broad subtropical ridge positioned
near the Azores. The pressure gradient between the
aforementioned 1023 mb high pressure system and lower pressures
in the deep tropics support fresh to strong easterly winds east
of 50W and north of 16N. Seas in these waters are 6 to 9 ft.
Elsewhere, moderate or weaker winds and moderate seas prevail.

For the forecast W of 55W, Hurricane Nigel is north of the area
near 33.2N 54.7W at 11 PM EDT, and is moving north at 13 kt.
Maximum sustained winds are 85 kt with gusts to 105 kt, and the
minimum central pressure is 971 mb. Nigel is forecast to
accelerate northeastward on Wed as IT pulls farther away from
the area. Strong winds and rough seas associated with Nigel will
continue to affect the forecast waters through Wed. A stationary
front extending from near 31N70W to Stuart, Florida will change
little through Thu. The frontal boundary should begin to slowly
lift northward on Fri as low pressure develops along it to the
east of northern Florida where gale conditions and rough seas
are possible Thu night into Fri. This non-tropical area of low
pressure could acquire some subtropical characteristics this
weekend while it moves generally northward.

$$
KRV
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