[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211200
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 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 0600 UTC surface analysis and satellite imagery through
1115 UTC.

...SPECIAL FEATURES...

Major Hurricane Fiona is centered near 24.2N 71.7W at 21/1200 UTC or
610 nm SW of Bermuda moving N at 7 kt. Estimated minimum central
pressure is 937 mb. Maximum sustained wind speed is 115 kt with
gusts to 140 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 are forecast to build to near 45 ft over the next
day or two. A drifting buoy from the Sofar network recently
measured seas of 25 ft, about 100 nm NE of the center of Fiona.
Heavy rains will continue to impact the Turks and Caicos through
this morning. Fiona is a category 4 hurricane on the Saffir-Simpson
Hurricane Wind Scale.  Some additional strengthening is forecast
through tonight, with some fluctuations in intensity possible on
Thursday. On the forecast track, the center of Fiona will
continue to move away from the Turks and Caicos today, and
approach Bermuda late on Thursday. 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 37.5N 42.6W at 21/0900
UTC or 740 nm W of the Azores moving NE at 14 kt. Estimated
minimum central pressure is 1000 mb. Maximum sustained wind
speed is 55 kt with gusts to 65 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 57/58W, moving W at 15-20 kt.
Scattered moderate and isolated strong convection is noted from
06N to 12N between 51W and 60W. Recent ASCAT data show strong
winds from 12N-15N between 55W-58W. Seas with this system are
likely as high as 8 to 9 ft currently. 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 southern Windward
Islands today and then move 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.

Please refer to the latest Atlantic Tropical Weather Outlook at
hurricanes.gov for more details.

...TROPICAL WAVES...

A Caribbean Sea tropical wave has its axis near 65W/66W, from 18N
southward to southern Venezuela, moving W at 15 kt. Isolated
showers are within 60 nm either side of the wave axis south of
13N.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes off the coast of southern Senegal near
12N17W to 1012 mb low pressure near 10N31W to 09N37W. The ITCZ
continues from 09N37W to 08N48W. Scattered moderate to strong
convection is noted from 10N-14N between 16W-19N. Scattered
moderate isolated strong convection is seen from 11N-14N between
29W-34W.

GULF OF MEXICO...

A 1016 mb high pressure is centered over west-central Mississippi.
A weak surface trough is oriented north-south just offshore the
west coast of the Florida peninsula. Isolated showers and tstorms
are noted along the trough from 26.5N-29N between 83W-84W.
Moderate NE winds prevail over the central Gulf of Mexico, where
seas are likely 3-5 ft. Gentle winds and 1-3 ft seas prevail
elsewhere across the Gulf.

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,
bringing a brief period of moderate to fresh N to NE winds to the
NE Gulf Fri.

CARIBBEAN SEA...

A recent ASCAT pass shows gentle winds across most of the
Caribbean Sea, except for moderate S winds from 15.5N northward
between 66W-71W, including the Mona Passage. Seas are 3-5 ft over
the eastern Caribbean and 1-3 ft in the western Caribbean.
Isolated moderate convection prevails over the central Caribbean
between 66.5W-74W. Scattered moderate convection is noted in the
far W Caribbean west of 83W from 11.5N-17N, mostly near the coasts
of Honduras and Nicaragua.

For the forecast, the tropical wave along 57W is forecast to move
west-northwestward across the southern Windward Islands late
today and then move toward the central Caribbean Sea late this
week. This system has a high chance of tropical cyclone formation
within the next 48 hours. For more information on this system,
please read the Special Features section above.

ATLANTIC OCEAN...

Please read the Special Features section above for information on
Major Hurricane Fiona.

Outside of Fiona and the tropical wave along 57W, no significant
or eventful weather is occurring in the basin. Winds are gentle to
moderate from 20N-31N between 20W-62W. Seas are 3-5 ft across this
area. The area of 20 kt or stronger winds directly associated
with the circulation of Hurricane Fiona currently extends from
19N-27N between 65W-75.5W. The area of 8 ft seas or greater
extends from 20N-28N between 67W-76W.

For the forecast W of 55W, Major Hurricane Fiona will move to
25.0N 71.7W this afternoon, 26.9N 71.1W Thu morning, 29.3N 69.8W
Thu afternoon, 32.3N 67.4W Fri morning, 36.5N 63.3W Fri afternoon,
and 42.0N 60.9W Sat morning. Fiona will weaken as an extratropical
cyclone near 50.0N 60.0W early Sun. 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
southward into the area Fri through Sat night followed by fresh
northeast winds. High pressure will build in behind the cold
front.

$$
GR
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