407
AXNT20 KNHC 250559
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Wed Sep 25 2024

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 0000 UTC surface analysis and satellite imagery through
0600 UTC.

...SPECIAL FEATURES...

Tropical Storm Helene is centered near 20.4N 85.9W at 25/0600
UTC or 60 nm E of Cozumel Mexico, moving NW at 9 kt. Estimated
minimum central pressure is 991 mb. Maximum sustained wind speed
is 50 kt with gusts to 60 kt. Seas 12 ft or greater are
occurring within 120 NM in the NE quadrant, 150 NM in the SE
quadrant, and 30 NM in the SW and NW quadrants, with peak seas
near 20 ft. Strong convection is occurring within 250 NM to the
north, east and south of the center, and additional moderate to
strong convection is noted across much of the western Caribbean
and southeastern Gulf of Mexico. Strengthening is forecast, and
Helene is expected to become a hurricane later tonight or early
Wednesday. The storm is forecast to rapidly strengthen over the
eastern Gulf of Mexico and become a major hurricane on Thursday.
Helene will strengthen to a hurricane near 21.1N 86.3W Wed
morning, move to 22.7N 86.4W Wed evening, then be near 25.4N 85.5W
Thu morning. Hurricane Helene will be at 29.5N 84.2W Thu evening,
then move inland and weaken to a tropical depression near 34.0N
84.5W Fri morning. Tropical Depression Helene will be well inland
in the southeastern U.S. by Friday evening. Helene is expected to
produce total rain accumulations of 4 to 8 inches over western
Cuba, the Cayman Islands and the northeast Yucatan Peninsula, with
isolated totals around 12 inches. This rainfall brings a risk of
considerable flooding. Over the Southeastern U.S., Helene is
expected to produce total rain accumulations of 4 to 8 inches with
isolated totals around 12 inches. This rainfall will likely
result in areas of considerable flash and urban flooding, with
areas of significant river flooding. Landslides are possible in
areas of steep terrain in the southern Appalachians. The
combination of a dangerous storm surge and the tide will cause
normally dry areas near the coast to be flooded by rising waters
moving inland from the shoreline, with impacts felt from the
Florida Keys to the panhandle of Florida, as well as northeastern
Florida through the central South Carolina coast. 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 Helene NHC Forecast Advisory and Public Advisory at
www.hurricanes.gov for more details.


Eastern Atlantic Tropical Wave: A tropical wave in the eastern
Atlantic has its axis along 30W from 06N to 19N, moving westward
at 10-15 kt. Scattered moderate convection is noted from 12N to
17N between 27W and 35W. Environmental conditions appear
favorable for gradual development of this system, and a tropical
depression is likely to form in a few days while it moves westward
to west-northwestward across the eastern and central tropical
Atlantic. There is a medium chance of tropical formation in the
next 48 hours, and a high chance of formation in the next seven
days.

...TROPICAL WAVES...

A tropical wave approaching the Lesser Antilles is near 53W from
17N southward, moving westward at 10-15 knots. Scattered moderate
to strong convection is occurring from 11N to 18N between 50W and
60W.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic near 12N17W, then curves
southwestward to near 07N40W. The ITCZ extends from 06N43W to
07N50W. Scattered moderate to locally strong convection is noted
generally along and within 300 nm south of the monsoon trough.

...GULF OF MEXICO...

Please refer to the Special Features section above for details on
Tropical Storm Helene. Fresh to strong E winds and seas are
increasing in the far SE Gulf of Mexico, including the Florida
Straits and Yucatan Channel, in association with Helene. Seas are
around 6 to 10 ft in this region. Weak ridging across the rest
of the basin supports light to gentle winds and slight seas.

For the forecast, Tropical Storm Helene will strengthen to a
hurricane near 21.1N 86.3W Wed morning, move to 22.7N 86.4W Wed
evening, then be near 25.4N 85.5W Thu morning. Hurricane Helene
will be at 29.5N 84.2W Thu evening, then move inland and weaken to
a tropical depression near 34.0N 84.5W Fri morning. Tropical
Depression Helene will be well inland in the southeastern U.S. by
Friday evening.

...CARIBBEAN SEA...

Please refer to the Special Features section above for details on
Tropical Storm Helene. Away from Helene, moderate to locally fresh
E winds and slight to moderate seas are occurring across much of
the basin.

For the forecast, Tropical Storm Helene will strengthen to a
hurricane near 21.1N 86.3W Wed morning, move to 22.7N 86.4W Wed
evening, then be near 25.4N 85.5W Thu morning. Hurricane Helene
will be at 29.5N 84.2W Thu evening, then move inland and weaken to
a tropical depression near 34.0N 84.5W Fri morning.

...ATLANTIC OCEAN...

Please refer to the Tropical Waves section for information on
potential tropical development in the eastern Atlantic this week.

A pair of surface troughs extend into the forecast waters south of
31N, one trough from 31N54W to 23N70W, and the other from 31N64W
to 25N70W and then to 30N79W. Scattered showers are observed just
ahead of these troughs. Elsewhere, a 1022 high dominates eastern
portions of the Atlantic. Moderate to fresh NE winds are occurring
north of 15N and east of 40W including the Canary Islands, along
with seas of 6 to 8 ft in this area. Gentle to moderate E winds
and seas of 4 to 7 ft prevail across the remainder of the
Atlantic.

For the forecast W of 55W, Tropical Storm Helene will strengthen
to a hurricane near 21.1N 86.3W Wed morning, move to 22.7N 86.4W
Wed evening, then be near 25.4N 85.5W Thu morning. Hurricane
Helene will be at 29.5N 84.2W Thu evening, then move inland and
weaken to a tropical depression near 34.0N 84.5W Fri morning. As
Helene moves across the eastern Gulf of Mexico, expect strong
winds and rough seas just E of the Florida Peninsula to about 78W.


$$
Adams