891
AXNT20 KNHC 251008
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 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 0600 UTC surface analysis and satellite imagery through
0930 UTC.

...SPECIAL FEATURES...

Tropical Storm Helene is centered near 20.7N 86.2W at 25/0900
UTC or 40 nm ENE of Cozumel Mexico, moving NW at 8 kt. Estimated
minimum central pressure is 985 mb. Maximum sustained wind speed
is 55 kt with gusts to 65 kt. Seas of 12 ft or greater are
occurring within 180 nm in the E semicircle and 60 nm in the W
semicircle. Numerous strong convection encompasses a broad area of
the western Caribbean and SE Gulf of Mexico, extending from 16N to
24N between 78W and 88W. Rapid strengthening is forecast, and
Helene is expected to become a hurricane today. Helene is then
forecast to intensify into a major hurricane in the eastern Gulf
of Mexico Thu morning. Major Hurricane Helene is likely to make
landfall in the Florida Panhandle by Thu night. 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 5
to 10 inches with isolated totals in excess of 15 inches. This
rainfall will likely result in 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: Broad low pressure is developing
in association with a tropical wave with an axis around 33W. The
low pressure is centered around 15N33W and is moving W at around
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 55W from
17N southward, moving westward at around 10 kt. Scattered
moderate to isolated strong convection is occurring from 11N to
18N between 50W and 60W.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic near 13N17W, then curves
southwestward to near 07N40W. The ITCZ extends from 06N43W to
07N51W. Scattered moderate 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. Strong E winds and rough to very rough seas
continue to increase in the SE Gulf of Mexico, including the
Florida Straits, this morning in association with Helene. In the
Yucatan Channel, tropical storm force winds and seas of up to 20
ft are ongoing. Moderate to fresh winds and seas of 3 to 6 ft are
also increasing in the NE and south-central Gulf of Mexico.

Elsewhere over the northern and western basin, weak high pressure
supports light to gentle winds and slight seas.

For the forecast, Tropical Storm Helene will strengthen to a
hurricane near 21.9N 86.5W this afternoon, then move to 24.1N
86.2W Thu morning. Hurricane Helene will be near 27.4N 85.0W Thu
afternoon, then make landfall and be near 32.0N 84.2W Fri
morning.

...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 21.9N 86.5W this afternoon, then move to 24.1N
86.2W Thu morning. Hurricane Helene will be near 27.4N 85.0W Thu
afternoon, then make landfall and be near 32.0N 84.2W Fri
morning.

...ATLANTIC OCEAN...

Please refer to the Special Features section above for details on
Tropical Storm Helene as well as low pressure forming in the
eastern Atlantic that is likely to have tropical development this
week.

Convection has dissipated overnight in association with two
surface troughs, one from 28N64W to 28N75W and the other from
27N56W to 23N70W. The only other significant areas of convection
in the basin are discussed above in the Special Features, Tropical
Waves, and Monsoon Trough sections. Elsewhere, most of the basin
is dominated by an Azores- Canary Islands high pressure. Moderate
to fresh NE to E winds are occurring from 15N to 25N E of 40W,
along with seas of 6 to 8 ft. 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 21.9N 86.5W this afternoon, then move to 24.1N
86.2W Thu morning. Hurricane Helene will be near 27.4N 85.0W Thu
afternoon, then make landfall and be near 32.0N 84.2W Fri
morning.

$$
Konarik