[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202200
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Tue Sep 20 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
2200 UTC.

...SPECIAL FEATURES...

Major Hurricane Fiona is centered near 22.6N 71.8W at 20/2100
UTC or 40 nm N of North Caicos Island moving NNW at 7 kt.
Estimated minimum central pressure is 957 mb. Maximum sustained
wind speed is 100 kt with gusts to 120 kt. Numerous moderate to
strong convection is noted within 120 nm of the center of Fiona.
Scattered numerous moderate to strong convection is elsewhere
from 18N to 28N between 64W and 74W. Seas are peaking near 36 ft.
Heavy rains around the center of Fiona will continue to impact
the Turks and Caicos through this evening with continued life-
threatening flooding. Localized additional flash and urban
flooding is possible in Puerto Rico and the Dominican Republic.
Fiona is forecast to continue strengthening over the next 48
hours, reaching category 4 intensity in the next day or so. Fiona
is forecast to turn northward while moving along the western
side of a mid-level anticyclone during the next day or so before
accelerating toward the north-northeast and northeast during the
latter part of the forecast period. 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.

Recently upgraded Tropical Storm Gaston is centered near 34.7N
44.4W at 20/2100 UTC or 860 nm W of the Azores moving NNE at 15
kt. Estimated minimum central pressure is 1009 mb. Maximum
sustained wind speed is 35 kt with gusts to 45 kt. Scattered
numerous moderate to strong convection is noted from 35N to 39N
between 41W and 46W. Please read the latest NHC
Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml
and Forecast/ Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details.

A tropical wave is located a few hundred miles east of the
Windward Islands. Low pressure along this wave near 10N56W
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 to 20 mph across the eastern and central
Caribbean Sea. Scattered moderate and isolated strong convection
is noted from 06N to 12N between 51W and 60W. Strong to near gale
force winds are noted within 180 nm north of the low center.
Seas are peaking near 10 ft. There is a medium chance for
tropical cyclone development in the next 48 hours, and a high
chance of tropical cyclone development over the next 5 days.
Please refer to the latest Atlantic Tropical Weather Outlook at
https://www.nhc.noaa.gov/gtwo.php?basin=atlc&fdays=2, 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 near 22.6N
71.8W 957 mb at 5 PM EDT moving NNW at 7 kt. Maximum sustained
winds 100 kt gusts 120 kt. Fiona will move to 23.6N 72.0W Wed
morning, 25.0N 71.9W Wed afternoon, 26.9N 71.3W Thu morning,
29.4N 70.1W Thu afternoon, 32.4N 67.8W Fri morning, and 36.9N
63.5W Fri afternoon. Fiona will become extratropical as it moves
to near 46.5N 60.0W Sat afternoon. 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 midweek. 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.

$$
AL
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