[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 220008
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Wed Sep 21 2022

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
2140 UTC.

...Updated information on Special Features and Tropical Waves
sections...

...SPECIAL FEATURES...

Major Hurricane Fiona is centered near 25.9N 71.54 at 22/0000 UTC
or 525 nm SW of Bermuda moving N at 8 kt. Estimated minimum
central pressure is 934 mb. Maximum sustained wind speed is 115
kt with gusts to 140 kt. Scattered to numerous moderate to strong
convection is within 90 nm of the center of Fiona. Scattered
moderate to strong convection is elsewhere from 22N to 30N between
62W and 74W. Seas are peaking near 42ft. Fiona will remain over
warm waters in a moist and unstable air mass for the next 48
hours. In this environment, some strengthening is still possible
within the next day or so, though eyewall replacement cycles could
cause some intensity fluctuations. The current forecast track
shifts Fiona north of 32N by Thu night. 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 NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

Tropical Storm Gaston is centered near 39.0N 40.0W at 21/2100
UTC or 610 nm W of the Azores moving NE at 12 kt. Estimated
minimum central pressure is 1000 mb. Maximum sustained wind
speed is 55 kt with gusts to 65 kt. Scattered moderate and
isolated strong convection is noted from 28N and 42W between 35W
and 42W. Please read the latest NHC Forecast/Advisory and Public
Advisory at www.hurricanes.gov for more details.

A tropical wave is producing shower and thunderstorm activity
near the southern Windward Islands and extreme southeastern
Caribbean Sea. The system continues to show signs of
organization, and it will likely become a tropical depression
within the next couple of days. The disturbance is forecast to
move west-northwestward across the eastern Caribbean Sea during
the next day or two, and be over the central Caribbean this
weekend. Regardless of development, locally heavy rainfall and
gusty winds are forecast to affect the Windward Islands tonight,
and northern Venezuela, northeastern Colombia, and the ABC island
chain during the next couple of days. There is a high chance of
tropical cyclone formation over the next 48 hours. Please refer to
the latest Atlantic Tropical Weather Outlook at hurricanes.gov
for more details.

Showers and thunderstorms located near the west coast of Africa are
associated with a tropical wave that is forecast to move over the
far eastern Atlantic waters on Thursday.  Thereafter, environmental
conditions are forecast to be conducive for some development, and a
tropical depression could form by this weekend while the system
moves slowly northward, between west Africa and the Cabo Verde
Islands. The chance of tropical cyclone formation during the next
48 hours is medium.

...TROPICAL WAVES...

Please see above for a tropical wave that is moving into the
eastern Caribbean with the potential for tropical cyclone
development.

...MONSOON TROUGH/ITCZ...

The monsoon trough exits the coast of Africa near 13N17W to low
pres near 11N32W to 09N38W. The ITCZ continues from 09N38W to
11N50. Aside from convection associated to the low pressure
center, scattered moderate convection is from 06N to 18N east of
18W to the coast of Africa.

GULF OF MEXICO...

High pressure prevails over the Gulf coast states. Gentle to
moderate winds prevail north of 25N, with light to gentle winds
south of 25N. Seas are in the 2-4 ft range over the NW Gulf and
1-3 ft elsewhere.

For the forecast, high pressure over the southeastern U.S. will
maintain gentle to moderate easterly breezes and slight seas the
next few days. A cold front is forecast to reach the NE Gulf on
Fri.

CARIBBEAN SEA...

A weak pressure gradient prevails across much of the area. Fresh
to locally strong winds associated to the strong tropical wave
are found over the far eastern Caribbean. Light to gentle winds
prevail elsewhere. Seas are in the 4-6 ft over the far eastern
Caribbean, and 1-3 ft elsewhere.

For the forecast, a tropical wave over the eastern Caribbean
along 62W continues to show signs of organization, and it will
likely become a tropical depression within the next couple of
days. The disturbance is forecast to move west-northwestward
toward the central Caribbean Sea later this week. Interests in
the Windward Islands should closely monitor the progress of this
system as heavy rainfall and gusty winds are affecting these
islands. Regardless of development, heavy rainfall is forecast to
affect northwestern Venezuela, northeastern Colombia, and the
ABC island chain later this week. An Air Force Reserve
reconnaissance aircraft is scheduled to survey the system this
evening.

ATLANTIC OCEAN...

Please read the SPECIAL FEATURES section above for information
about Major Hurricane Fiona.

Outside of Fiona, high pressure prevails across the tropical and
subtropical waters east of 60W. Winds over this area are in the
gentle to moderate range, with seas of 3-5 ft. South of 20N,
an area of low pressure is embedded within the monsoon trough
near 11N32W. Moderate winds prevail across the waters south of
20N, with seas in the 3-5 ft range.

For the forecast W of 55W, Major Hurricane Fiona near 25.6N
71.5W 937 mb at 5 PM EDT moving N at 8 kt. Maximum sustained
winds 115 kt gusts 140 kt. Fiona will move to 27.0N 71.0W Thu
morning, 29.5N 69.6W Thu afternoon, 32.6N 66.9W Fri morning,
37.4N 63.0W Fri afternoon, become extratropical and move to 43.5N
61.1W Sat morning, and 47.0N 61.0W Sat afternoon. Fiona will
weaken as an extratropical cyclone near 52.5N 60.5W Sun
afternoon. Swells generated by Fiona will continue to spread
westward across the southwestern Atlantic toward the northwestern
Bahamas and the east coast of the United States during the next
day or two. The swells could cause life-threatening surf and rip
current conditions. A cold front will drop south over the north
waters early on Fri through Sat night followed by fresh northeast
winds and building seas. High pressure will build in behind the
cold front.

$$
AL/Hagen
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