[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 210321
TWDAT

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

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.

...Updated Special Features...

Based on 1800 UTC surface analysis and satellite imagery through
2200 UTC.

...SPECIAL FEATURES...

Major Hurricane Fiona is centered near 23.2N 71.8W at 21/0300 UTC
or 80 nm N of North Caicos Island moving N at 7 kt. Estimated
minimum central pressure is 947 mb. Maximum sustained wind speed
is 110 kt with gusts to 135 kt. Satellite imagery shows a clear
eye 25 nm in diameter. Numerous moderate to strong convection is
noted within 300 nm of center in the NE quadrant, 270 nm SE
quadrant, 120 nm SW quadrant and 180 nm NW quadrant. Peak seas are
estimated at 36 ft currently and and forecast to build to near 45
ft over the next day or two. Heavy rains will continue to impact
the Turks and Caicos through tonight. Localized additional flash
flooding remains possible in the Dominican Republic. Fiona is
forecast to continue strengthening over the next 12 hours,
reaching category 4 intensity on Wed. Fiona is forecast to turn to
the NNE and accelerate on Thu. 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 36.2N 43.6W at 21/0300 UTC
or 800 nm W of the Azores moving NNE at 16 kt. Estimated minimum
central pressure is 1004 mb. Maximum sustained wind speed is 45
kt with gusts to 55 kt. Scattered moderate isolated strong
convection is noted within 180 nm of the center in the NE
quadrant, 30 nm SE quadrant and 90 nm W semicircle. A turn to the
NE and then E is expected over the next 48 hours. 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.

A tropical wave has an axis along 56/57W, moving W at 15-20 kt.
The system continues to show signs of organization and it will
likely become a tropical depression within the next two or three
days. The disturbance is forecast to move west-northwestward
across the southern Windward Islands late Wednesday and then move
toward the central Caribbean Sea late this week. Interests in the
Windward Islands should closely monitor the progress of this
system as heavy rainfall and gusty winds could affect these
islands beginning on Wednesday. Scattered moderate and isolated
strong convection is noted from 06N to 12N between 51W and 60W.
Recent ASCAT data show strong winds with the wave from 12N-15N
between 55W-58W. Seas are peaking near 10 ft. There is a high
chance of tropical cyclone development within the next 48 hours.
Please refer to the latest Atlantic Tropical Weather Outlook at
hurricanes.gov for more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave has its axis near 63W, from 20N
southward, moving westward from 10 knots to 15 knots. Limited
convection is over the Caribbean waters with this tropical wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes off the coast of Africa near 12N17W to
10N37W. The ITCZ continues from 10N37W to 09N48W. Scattered
moderate and isolated strong convection is noted from 08N to 13N
between 30W and 35W.

GULF OF MEXICO...

High pressure prevails over the SE United States. A surface
trough extends from southern Florida southward across eastern
Cuba. A second surface trough extends from 26N85W to the Yucatan
Channel. The pressure gradient between this area of high pressure
and the surface trough is supporting gentle to moderate winds
over the NE Gulf. Light to gentle winds prevail elsewhere. Seas
are in the 2-4 ft range, except for the SE Gulf where seas of 1-3
ft prevail.

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 could reach the NE Gulf on Fri.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section above for more on the
potential for tropical cyclogenesis associated with an area of
low pressure along a tropical wave that will move into the
Caribbean in the next couple of days.

Fresh to locally strong winds prevail over the north central
Caribbean around the periphery of Hurricane Fiona. Gentle to
moderate winds are elsewhere across the south central and eastern
Caribbean. Light to gentle winds are over the western Caribbean.
Seas are in the 4-6 ft range over the north central Caribbean,
2-4 ft over the south central and eastern Caribbean, and 1-3 ft
over the western Caribbean.

For the forecast, a tropical wave, currently located east of the
Windward Islands near 56W, continues to show signs of
organization. Additional development is expected, and a tropical
depression is likely to form within the next few days as the
system moves westward to west-northwestward at 15 kt across the
eastern and central Caribbean Sea. Interests in the Windward
Islands should closely monitor the progress of this system as
heavy rainfall and gusty winds could affect these islands
beginning on Wednesday.

ATLANTIC OCEAN...

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

Outside of Fiona, a surface trough is found off the NE coast of
Florida, with light to gentle winds in its vicinity. High
pressure generally prevails elsewhere over the tropical and
subtropical waters north of 20N. Light to gentle winds are noted
north of 23N between 40W and 60W, with gentle to moderate winds
elsewhere north of 20N. Seas of 4-6 ft prevail over these waters.
South of 20N, outside of the tropical wave mentioned in the
SPECIAL FEATURES section above, gentle to moderate winds and seas
of 4-6 ft prevail.

For the forecast W of 55W, Major Hurricane Fiona will move to near
26N71.5W Wed evening, 31N69W Thu evening, and near 39.5N62W Fri
evening. Swells generated by Fiona will continue to spread
westward across the southwestern Atlantic toward the central and
northwestern Bahamas and the east coast of the United States
through late week. A cold front will drop south over the northern
and central waters Fri through Sat night followed by fresh
northeast winds and building seas. High pressure will build in
behind the cold front.

$$
Hagen
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