[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192222
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 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 1800 UTC surface analysis and satellite imagery through
2130 UTC.

...SPECIAL FEATURES...

Hurricane Nigel is centered near 31.8N 54.7W at 19/2100 UTC or
510 nm E of Bermuda, moving NNW at 12 kt. Estimated minimum
central pressure is 974 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 29N to 35N between 51W and 58W. Hurricane Nigel,
currently a Category Two on the Saffir-Simpson Hurricane Wind
Scale, is forecast to turn northward tonight, then NE Wed. Nigel
is likely to accelerate northeastward starting Wed night. Further
strengthening is likely through Wed, but weakening will likely
begin Wed night and Thu. Nigel is forecast to become a strong
post- tropical cyclone on Friday. Swells generated by Nigel are
expected to affect Bermuda through Wed. 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.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 25W, through
the Cabo Verde islands, moving westward at around 10 kt.
Scattered moderate convection is noted near the monsoon trough
from 05N to 12N between 20W and 28W.

A central Atlantic tropical wave has its axis along 46W, south of
14N, moving westward at around 10 kt. Numerous moderate to
isolated strong convection is observed from 06N to 12N and
between 41W and 49W.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Senegal near 15N17W and continues southwestward to 09N30W and then
westward to 09N47W. The ITCZ extends from 09N47W to 09N59W. Other
than the convection described in the TROPICAL WAVES section
above, scattered moderate to isolated strong convection is present
from 03N to 15N and between 28W and 41W and from 05N to 14N
between 48W and 54W. Scattered moderate convection has also
developed from 06N to 11N, E of 20W.

...GULF OF MEXICO...

A stationary front extends from near Sarasota, Florida, westward
to near 25N95W. Scattered moderate convection is noted within 90
nm of the boundary. Gentle to moderate easterly winds and seas of
2-4 ft are evident north of the front. Light to gentle winds and
seas of 1-3 ft are found south of the boundary.

For the forecast, the stationary front will dissipate tonight.
Then, a ridge will dominate the basin producing gentle to moderate
E to SE winds and slight seas, pulsing to moderate to fresh
offshore the W Yucatan in the evenings. A developing low pressure
E of Florida will tight the pressure gradient over the NE Gulf
bringing fresh NE winds by 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 SW 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 northern Colombian and NW Venezuelan
coasts. Seas in the central Caribbean are 4 to 7 ft. Elsewhere,
light to gentle winds and seas of 2-4 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.

A stationary front extends southwestward from 31N71W to near West
Palm Beach, Florida, with scattered moderate convection within 90
nm on both sides of the boundary. Moderate or weaker winds and
2-4 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 1024 mb high pressure system and lower pressures
in the deep tropics support fresh to strong easterly winds winds
east of 45W and north of 15W. Seas in these waters are 6-9 ft.
Elsewhere, moderate or weaker winds and moderate seas prevail.

For the forecast W of 55W, Hurricane Nigel is just N of the area
near 31.8N 54.7W at 5 PM EDT, and is moving north-northwest at 12
kt. Maximum sustained winds are 85 kt with gusts to 105 kt, and
the minimum central pressure is 974 mb. 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 South 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. Regardless of subtropical development, this low is
likely to bring gusty winds, heavy rain, and high surf conditions
to portions of the coastal Carolinas into the coastal Mid-Atlantic
states late this week into this weekend.

$$
KONARIK
This weather bulletin was brought to you by:
www.nashvilleweather.net