[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 241707
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sat Sep 24 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...

FIONA...

Post-Tropical Cyclone Fiona is centered near 47.9N 61.3W at
24/1500 UTC or 90 nm WNW of Port Aux Basques Newfoundland moving
N at 22 kt. Estimated minimum central pressure is 945 mb.
Maximum sustained wind speed is 70 kt with gusts to 85 kt. Fiona
has slowed down. On the forecast track, Fiona will move across
the Gulf of St. Lawrence through tonight, across Labrador early
Sun, then the Labrador Sea Sun night. Fiona continues to produce
hurricane- force winds, heavy rains, storm surge, and rough marine
conditions across Atlantic Canada and the surrounding waters.
Seas are peaking to 60 ft near the center. Heavy rains from Fiona
are expected to continue to impact portions of Nova Scotia,
Prince Edward Island, and western Newfoundland today, persisting
across eastern Quebec and Labrador into Sunday. This rainfall is
expected to produce flooding, some of which could be significant.
Large swells generated by Fiona are expected to cause life-
threatening surf and rip current conditions along the coast of the
northeast United States, Bermuda, and Atlantic Canada during the
next couple of days.

Please read the latest High Seas Forecast issued by the Ocean
Prediction Center at website
https://ocean.weather.gov/shtml/NFDHSFAT1.php and the latest NHC
Forecast/Advisory and Public Advisory at www.hurricanes.gov for
more details.

GASTON...

Tropical Storm Gaston is centered near 38.0N 30.8W at 24/1500
UTC or 100 nm WSW of Faial Island In The Central Azores moving
WSW at 8 kt. Estimated minimum central pressure is 1001 mb.
Maximum sustained wind speed is 40 kt with gusts to 50 kt, with
very rough seas near the center. Gaston has now turned WSW, and
this continued motion should keep Gaston moving through the
western Azores today. Tropical storm conditions over the western
and central Azores today should diminish today as Gaston moves
away from the islands. Gaston is expected to produce heavy
rainfall over the western and central Azores through Saturday.
This rainfall may result in landslides and areas of flooding.

Please read the latest High Seas Forecast issued by the Ocean
Prediction Center at website
https://ocean.weather.gov/shtml/NFDHSFAT1.php and the latest NHC
Forecast/Advisory and Public Advisory at www.hurricanes.gov for
more details.

HERMINE...

Tropical Storm Hermine is centered in the eastern Atlantic near
20.8N 20.8W at 24/1500 UTC or 340 nm NNE of the Cabo Verde Islands
moving N at 7 kt. Estimated minimum central pressure is 1002 mb.
Maximum sustained wind speed is 35 kt with gusts to 45 kt with
rough seas near and to the north of the center. Hermine remains
strongly sheared with an exposed center to the southwest of
scattered moderate to isolated strong convection. A northward
motion will continue through tonight before a turn toward the left
Sun. Some weakening expected Sun, and Hermine could become a
remnant low on Mon.

Please read the latest High Seas Forecast issued by
Meteo-France at website http://weather/gmdss.org/ll.html and the
latest NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

IAN...

Tropical Storm Ian is centered in the Caribbean Sea near 14.4N
75.2W at 24/1500 UTC or 230 nm SSE of Kingston Jamaica moving W at
13 kt. Estimated minimum central pressure is 1003 mb. Maximum
sustained wind speed is 40 kt with gusts to 50 kt. Seas are
peaking at 8 to 10 ft near and NE of the center. Numerous moderate
to scattered strong convection is noted from 12N to 17N between
73W and 78W. A generally westward motion is expected through
tonight, followed by a turn to the NW Sun and NNW Mon as it moves
across the northwestern Caribbean Sea. Strengthening is forecast
over the next few days. Ian is expected to become a hurricane by
late Sun and approaching western Cuba at or near major hurricane
strength by Mon night.

A W to WNW motion is expected through early Sun,
followed by a NW turn late Sun, and a NNW turn by late Mon. On
this forecast track, Ian will move across the central Caribbean
Sea today, pass SW of Jamaica on Sun, and then very close to the
Cayman Islands Sun night through early Mon. Ian is likely to
approach western Cuba Mon. Strengthening is forecast for the next
few days, and Ian is likely to become a hurricane by Sun night.
Ian is expected to produce heavy rainfall, flash flooding, and
possible mudslides in areas of higher terrain, particularly over
Jamaica and Cuba. Limited flash and urban flooding is possible with
rainfall across the Florida Keys and Florida peninsula through mid
next week. Ian is forecast to move near or over western Cuba and approach
the west coast of the Florida peninsula at or near major hurricane
strength early next week, where there is increasing confidence in
multiple life-threatening hazards: storm surge, hurricane-force
winds and rainfall flooding. While it is too soon to determine the
exact magnitude and location of these hazards, residents in Cuba,
the Florida Keys, and the Florida peninsula should ensure they have
their hurricane plan in place, follow any advice given by local
officials, and closely monitor updates to the forecast. Please
consult products from your local weather office for more details.

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 WAVES...

There are no tropical waves present based on the latest analysis.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends west-southwestward from near the Cabo
Verde Islands at 15N24W through a 1009 mb low centered near
12N36W to 09N42W. An ITCZ then continues from 09N42W to 08N60W.
Scattered moderate convection is noted within 120 nm in the NW
semicircle of the low near 12N36W.

...GULF OF MEXICO...

Please refer to the Special Features section above on Tropical
Storm Ian, which is anticipated to impact the eastern Gulf early
next week.

A stationary front extends over the eastern Gulf, from near Port
Charlotte, Florida to 27N85W. A few showers and thunderstorms are
active about 90 nm south of Panama City, Florida, associated with
a weak developing trough. Isolated showers and thunderstorms are
also active in the far southwest Gulf. A weak pressure pattern
continues across the basin, supporting light breezes and slight
seas in most areas.

For the forecast, conditions will begin to deteriorate
across the eastern Gulf of Mexico by early next week as the center
of Ian emerges from Cuba. Gulf coast residents and mariners in the
region should follow the latest advisories over the next several
days on Ian and make preparations accordingly.

...CARIBBEAN SEA...

Please refer to the Special Features section above on Tropical
Storm Ian moving across the basin.

Outside of the main impacts of T.S. Ian across the central
Caribbean, no significant shower or thunderstorm activity is
evident at this time. Moderate E to SE winds and slight to
moderate seas are observed across the eastern Caribbean, and light
to gentle NE breezes and slight seas are noted over the northeast
Caribbean.

For the forecast, Ian will move to 14.5N 76.8W this evening, 15.5N 78.9W Sun
morning, strengthen to a hurricane near 17.0N 80.7W Sun evening,
18.8N 82.3W Mon morning, 20.7N 83.4W Mon evening, and 22.7N 84.1W
Tue morning. Ian will change little in intensity as it moves near
26.0N 83.9W by early Wed. Deteriorating marine conditions can be
expected near the track of Ian, including the central Caribbean
through early Sun, and portions of the northwest Caribbean later
on Sun through Tue. Heavy rainfall and hazardous marine conditions
will impact waters near Jamaica, the Cayman Islands and Cuba.

...ATLANTIC OCEAN...

Please refer to the Special Features section above on Post-
tropical Cyclone Fiona and Tropical Storms Gaston and Hermine in
the Atlantic Basin.

A weak cold front extends from SE of Bermuda near 31N61W to 27N72W,
where it becomes stationary and extends across the northern
Bahamas to near Jupiter Inlet, Florida. Scattered moderate
convection is noted from 120 to 150 nm of this boundary north of
26N. A few showers and thunderstorms are also evident along the
stationary boundary over the northern Bahamas. Refer to the
Monsoon Trough/ITCZ section above for additional convection in the
Atlantic Basin. Buoy and altimeter satellite data indicate 8 to 10
ft seas mainly north of 26N between 60W and 75W. This is mainly
northerly swell associated with the passage of Fiona across the
western Atlantic. Elsewhere, outside of the main areas of impact
associated with Hermine, mostly gentle to moderate trade winds
and moderate seas are noted across the basin.

For the forecast W of 55W, swells from extratropical cyclone
Fiona continue across the forecast waters N of 27N and W of 55W.
This swell will continue to propagate eastward while dissipating.
Conditions are expected to improve by Mon morning. Tropical Storm
Ian is near 14.4N 75.2W 1003 mb at 11 AM EDT moving W at 13 kt.
Maximum sustained winds 40 kt gusts 50 kt. Ian will move to 14.5N
76.8W this evening, 15.5N 78.9W Sun morning, strengthen to a
hurricane near 17.0N 80.7W Sun evening, 18.8N 82.3W Mon morning,
20.7N 83.4W Mon evening, and 22.7N 84.1W Tue morning. Ian will
change little in intensity as it moves near 26.0N 83.9W by early
Wed. Impacts from Ian may impact areas offshore Florida early next
week.

$$
Christensen
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