[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291229
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Thu Sep 29 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.

Based on 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...Updated 1230 UTC for Tropical Storm Ian Special Feature...

...SPECIAL FEATURES...

Tropical Storm Ian is centered near 28.5N 80.7W at 29/1200 UTC or
10 nm W of Cape Canaveral, Florida moving NE at 7 kt. Estimated
minimum central pressure is 987 mb. Maximum sustained wind speed
is 55 kt with gusts to 65 kt. Tropical storm force winds extend
outward up to 360 nm from the center in the NE quadrant, 200 nm NW
quadrant and 120 nm S semicircle. Peak seas over Atlantic waters
offshore north Florida are 20 ft. Peak seas over the eastern Gulf
of Mexico offshore have subsided now to 13 ft. Numerous moderate
and isolated strong convection extends outward from the center 360
nm in the E semicircle, 75 nm SW quadrant and 210 nm NW quadrant.
A band of thunderstorms also extends east of Ian, extending
southward over the central Bahamas. Several Flash Flood
Emergencies are in effect over portions of central and northern
Florida this morning. On the forecast track, the center of Ian is
expected to move off the east-central coast of Florida soon and
then approach the coast of South Carolina on Friday. Some re-
intensification is forecast, and Ian could be near hurricane
strength when it approaches the coast of South Carolina on Friday.
Please read the latest High Seas Forecast issued by the National
Hurricane Center at 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 Depression Eleven is centered near 17.8N 36.1W at
29/0900 UTC or 700 nm W of the Cabo Verde Islands moving NW at
11 kt. Estimated minimum central pressure is 1008 mb. Maximum
sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are
near 10 ft. Numerous moderate to isolated strong convection is
mainly NE of the center, from 17N to 21N between 33W and 36W.
A general north to northwest motion is expected over the next
couple days before the system dissipates by Friday or Saturday.
Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml for more
details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave axis extends along 29W from 08N
to 20N, moving W at 10 kt. A cluster of moderate convection has
developed from 11N to 15N between 28W and 30W.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Senegal near 14N16W
to 10N45W. The ITCZ continues from 10N45W to 12N59W. Scattered
moderate convection is currently observed from 07N to 15N, within
300 nm of the African coast, and slowly drifting west. Convection
is limited across the remainder of the monsoon trough/ITCZ
boundaries.

GULF OF MEXICO...

Please see Special Features section above for details on Tropical
Storm Ian, that is moving NE across Florida and gradually away
from the area.

Northerly flow W of Ian is dominating the basin. Winds are strong
to near gale force in the northeast Gulf and moderate to fresh
elsewhere. The except is offshore Veracruz, where locally strong
NW winds are occurring within 60 nm of the coast.

Large swell generated by Ian is also encompassing much of the
basin. Seas are 10 to 14 ft across the eastern Gulf, 8 to 11 ft in
the central and NW Gulf, and 6 to 8 in the SW Gulf. These seas
will gradually decay into tonight.

For the forecast, Tropical Storm Ian will move to 28.9N 80.4W
this afternoon, 30.2N 80.0W Fri morning, and 32.2N 80.1W Fri
afternoon. Tropical Storm Ian will move inland to 34.3N 80.8W Sat
morning, then weaken to a tropical depression over North Carolina
Sat afternoon. Ian will dissipate Sun morning. Elsewhere moderate
to fresh E to SE winds will persist through late Fri. Looking
ahead, winds and seas will diminish across the region Sat into
Sun. Winds and seas will gradually diminish across the northeast
Gulf tonight through Fri, with light breezes and slight seas
persisting across the basin thereafter. Looking ahead, a cold
front may enter the northeast Gulf late Sat or Sun then stall and
dissipate.

CARIBBEAN SEA...

An upper-level trough with an axis from roughly Puerto Rico to the
Venezuela-Colombia border is generating scattered moderate
convection in a zone from 11N to 17N between 64W and 72W. A
surface trough in the NW Caribbean from western Cuba to Belize is
leading to scattered moderate convection in and near the Gulf of
Honduras.

Behind the aforementioned surface trough, moderate NW winds are
occurring. Elsewhere, winds are mainly gentle. Seas across the
basin are 2 to 4 ft, except through  the Yucatan Passage, where
northerly swell generated by Ian is causing seas of 6 to 10 ft.

For the forecast, the large N swell from Ian will continue to
spread through the Yucatan Channel through tonight. Elsewhere
gentle to moderate winds and slight to moderate seas will persist
across the basin.

ATLANTIC OCEAN...

See the Special Features Section above for more information on
Tropical Storm Ian and Tropical Depression Eleven.

Tropical Storm Ian is dominating weather N of 24N and W of 73W,
with hazardous marine conditions. Elsewhere, an upper level trough
that extends across Puerto Rico and continues S through the
Caribbean has an associated surface trough that is located from
Puerto Rico NE to 25N61W. Scattered moderate convection is noted
with this trough from 18N to 25N between 61W and 69W. Another
surface trough is noted from 31N32W to 24W37W. This trough is
inducing scattered moderate convection N of 27N between 32W and
39W.

W of 55W, mainly moderate W winds prevail. In the far E Atlantic,
moderate to fresh winds are present N of the monsoon trough and E
of 35W, and are highest near the Moroccan coast and between
mainland Africa and the Cabo Verde Islands. Elsewhere in the
basin, aside from the in the vicinity of Tropical Depression
Eleven, winds are mainly gentle.

Away from the influence of Tropical Storm Ian and Tropical
Depression Eleven, basin-wide seas range from 4 to 7 ft.

For the forecast west of 55W, Tropical Storm Ian will move to
28.9N 80.4W this afternoon, 30.2N 80.0W Fri morning, and 32.2N
80.1W Fri afternoon. Tropical Storm Ian will move inland to 34.3N
80.8W Sat morning, then weaken to a tropical depression over North
Carolina Sat afternoon. Ian will dissipate Sun morning. Elsewhere
moderate to fresh E to SE winds will persist through late Fri.
Looking ahead, winds and seas will diminish across the region Sat
into Sun.

$$
Hagen/Konarik
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