[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161758
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Fri Sep 16 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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...SPECIAL FEATURES...

Tropical Storm Fiona is centered near 16.2N 60.3W at 16/1800 UTC
or 65 nm E of Guadeloupe moving W at 12 kt. Estimated minimum
central pressure is 1005 mb. Maximum sustained wind speed is 45 kt
with gusts to 55 kt. Peak seas of 21 ft are near and northeast of
the center. Seas 12 ft or greater extend from the center of Fiona
to 300 nm in the NE quadrant, 300 nm in the NW quadrant, 90 nm in
the SW quadrant, and 120 nm in the SE quadrant. Fiona remains
sheared, with numerous moderate scattered strong convection from
15N to 17N between 57W and 60W. Additional scattered moderate
convection is from 13N to 15N between 55W and 58W. A westward
motion with a decrease in forward speed is expected through early
Sunday, followed by a turn toward the west- northwest and
northwest Sunday and Sunday night. On the forecast track, the
center of Fiona is expected to move across the Leeward Islands
tonight, near or just south of the Virgin Islands and Puerto Rico
Saturday into Sunday, and approach the southern coast of the
Dominican Republic Sunday night and early Monday. Tropical storm
conditions are expected across portions of the Leeward Islands
within the warning area beginning this afternoon and continuing
through Saturday. Tropical storm conditions will spread westward
to the U.S. and British Virgin Islands on Saturday, and across
Puerto Rico late Saturday and Saturday night. Tropical storm
conditions are possible on Dominica this evening or tonight and
across the watch area in the Dominican Republic beginning late
Sunday. Heavy rains from Fiona will reach the Leeward Islands by
this evening, spreading to the British and U.S. Virgin Islands and
Puerto Rico Saturday, reaching the Dominican Republic Sunday, and
the Turks and Caicos Monday night or Tuesday. This rainfall may
produce considerable flood impacts including flash and urban
flooding, along with mudslides in areas of higher terrain. Swells
generated by Fiona are affecting the Leeward and northern Windward
Islands, and are expected to spread westward to the Virgin
Islands and Puerto Rico today. Swells will then reach the northern
coast of Hispaniola, the Turks and Caicos Islands, and the
southeastern Bahamas over the weekend. These conditions could
cause life-threatening surf and rip current conditions. For storm
information specific to your area in the United States, including
possible inland watches and warnings, please monitor products
issued by your local National Weather Service forecast office. For
storm information specific to your area outside of the United
States, please monitor products issued by your national
meteorological service.

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
T.S. Fiona NHC Forecast/Advisory and NHC Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis along 27W from
05N to 15N moving westward at 15-20 kt. Scattered showers are in
the vicinity of this tropical wave.

A central Atlantic tropical wave has its axis along 74W from 08N
to 21N moving westward at 15 kt. Scattered moderate convection is
from 18N to 20N between 37W and 40W. Scattered showers are also
noted from 20N to 23N between 37W and 41W. Per the latest tropical
weather outlook, this tropical wave has a low chance of
development over the next 48 hours and five days.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the northern border of The
Gambia near 14N17W southwestward to 08N24W to and northwest to
11N33W. Scattered moderate convection is from 04N to 08N east of
18W.

GULF OF MEXICO...

A trough is analyzed in the W Bay of Campeche from 19N94W to
23N97W. Scattered moderate convection is within 90 nm of either
side of the trough axis. Another trough extends from the NE Gulf
near 28N85W to the south-central Gulf near 22N89W. Scattered
moderate convection is from 24N to 28N east of 84W to the Florida
Gulf Coast. Gentle to moderate E winds and 1-3 ft seas prevail
across the basin. Winds and seas may be locally higher in the
aforementioned areas of convection.

For the forecast, high pressure over the southeastern U.S. will
continue to maintain gentle to moderate easterly breezes and
slight seas through early next week. A surface trough over the
eastern Gulf will support scattered showers and thunderstorms over
the southeastern Gulf into Sat.

CARIBBEAN SEA...

Please see the SPECIAL FEATURES section for information on
Tropical Storm Fiona, which is forecast to impact the NE
Caribbean.

1011 mb Colombian/Panamanian Low is centered near 10N80W along
the extension of the East Pacific Monsoon Trough in the SW
Caribbean. Scattered moderate isolated strong convection is from
09N to 12N west of 76W. Scattered moderate convection is from 12N
to 16N between 81W and 83W. Scattered moderate convection is also
within 60 nm of the coast of NE Honduras. Scattered showers are
noted in the central Caribbean. In the E Caribbean, gentle to
moderate NE flow is evident ahead of TS Fiona, and seas are 4-6
ft. The pressure gradient between the subtropical Atlantic high
pressure and the Colombian/Panamanian low supports fresh trades in
the north- central Caribbean, diminishing to gentle to moderate
in the south- central Caribbean. Seas in the central and SW
Caribbean are 4-6 ft. Trades are gentle to moderate in the W
Caribbean, with 3-5 ft seas.

For the forecast, Tropical Storm Fiona is near 16.2N 60.3W 1005
mb at 2 PM EDT moving W at 12 kt. Maximum sustained winds are
near 45 kt with gusts to 55 kt. Fiona will move to near 16.5N
63.5W early Sat, near 17.5N 67.5W early Sun, and strengthen to a
60 kt tropical storm before moving near Hispaniola Mon morning
near 18.5N 69.5W. Fiona will then move to near 20.5N 71.5W Tue
morning, then strengthen to a hurricane Wed morning near 22.5N
72.5W.

ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section for information on
Tropical Storm Fiona.

A weak cold front enters the W Atlantic discussion waters near
31N73W to 29N77W. A surface trough parallels the Florida Atlantic
coast along 80W. Scattered moderate convection is currently
limited to the northern Bahamas. 1021 mb high pressure is centered
near 30N57W. 1023 mb high pressure is near 30N25W. A weak surface
trough enters the central Atlantic discussion waters near 31N39W
and extends to 29N45W. Outside of the waters impacted by TS Fiona,
gentle to moderate anticyclonic flow persists along the southern
periphery of the aforementioned high pressures. Seas are 4-7 ft
across the basin. In the far E Atlantic, an area of fresh NE winds
is evident on this morning's scatterometer data, from 17N to 22N
east of 25W. Seas are 6-8 ft in this area of fresh winds.

For the forecast west of 55W, Tropical Storm Fiona is near 16.2N
60.3W 1005 mb at 2 PM EDT moving W at 12 kt. Maximum sustained
winds are near 45 kt with gusts to 55 kt. Fiona will move to near
16.5N 63.5W early Sat, near 17.5N 67.5W early Sun, and strengthen
to a 60 kt tropical storm before moving near Hispaniola Mon
morning near 18.5N 69.5W. Fiona will then move to near 20.5N 71.5W
Tue morning, then strengthen to a hurricane Wed morning near
22.5N 72.5W. A cold front extends from 31N74W to 28.5N79W. The
cold front will shift slowly eastward through the weekend.
Moderate northeast winds north of the frontal boundary will
continue through the most of the weekend. Scattered showers and
thunderstorms are expected near the frontal boundary.

$$
Mahoney
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