259
AXNT20 KNHC 270603
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Fri Sep 27 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
0540 UTC.

...SPECIAL FEATURES...

The hazards for land are: storm surge, wind, rainfall, tornadoes,
and surf.

The center of Hurricane Helene, at 27/0600 UTC, is inland, close
to 31.2N 83.3W. This position is also about 111 nm/120 km to the
NW of Cedar Key in Florida; and about 70 km to the SE of
Tallahassee in Florida. Helene is moving toward the NNE, or 015
degrees 21 knots. The estimated minimum central pressure is 938
mb. The maximum sustained wind speeds are 120 knots with gusts to
140 knots. Hurricane-force winds are within:
50 nm of the center in the NE quadrant; 50 nm of the center in the
SE quadrant; 30 nm of the center in the SW quadrant; and 40 nm of
the center in the NW quadrant. Wind speeds of 50 knots are
within: 100 nm of the center in the NE quadrant; 100 nm of the
center in the SE quadrant; 50 nm of the center in the SW quadrant;
and 50 nm of the center in the NW quadrant. Tropical storm-force
winds are within: 240 nm of the center in the NE quadrant; 270 nm
of the center in the SE quadrant; 100 nm of the center in the SW
quadrant; and 120 nm of the center in the NW quadrant. The sea
heights of 12 feet or greater are within:
150 nm of the center in the NE quadrant; 340 nm of the center in
the SE quadrant; 420 nm of the center in the SW quadrant; and 120
nm of the center in the NW quadrant. The maximum sea height value
is 35 feet. Expect: strong to near gale-force winds, and rough
seas, elsewhere within 31N76W 29N83W 31N87W 30N93W 24N84W 24N79W
31N76W...including in the Straits of Florida and in the Atlantic
Ocean exposures. Expect: wind speeds 20 knots or less, and rough
seas in mixed swell, for the remainder of the area within 28N92W
30N93W 27N96W 22N93W 20N86W 21N79W 28N92W...including in the
Straits of Florida and in the Yucatan Channel. Precipitation:
numerous strong is within 250 nm of the center in the N
semicircle. Scattered to numerous strong is close to the NW
Bahamas 25N to 29N between 78W and 80W. Isolated moderate to
locally strong is in Florida and in the Gulf of Mexico from 28N
southward, including in the Yucatan Channel, and in parts of the
NW Caribbean Sea.

Please, read the latest HIGH SEAS FORECAST, that is issued by the
National Hurricane Center, at the 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.

...CENTRAL ATLANTIC OCEAN INVEST 98L...

A 1007 mb low pressure center is near 16N, along a 40W tropical
wave. The tropical wave is from 20N southward, moving westward 10
knots to 15 knots. The chance of this feature developing into a
tropical cyclone during the next 48 hours is high. This system
does not have a well-defined surface circulation yet. A tropical
depression is expected to form tonight or on Friday. The movement
of this feature will be toward the west to west-northwest 10 mph
to 15 mph. Precipitation: scattered to numerous strong is 180 nm
of the center in the N semicircle.

Please read the latest Tropical Weather Outlook issued by the
National Hurricane Center at hurricanes.gov

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 24W, from 20N southward,
moving westward 10 knots to 15 knots. Precipitation: scattered
moderate to strong is from 14N to 17N between 22W and 25W, and
from 16N to 19N between 19W and 22W.

A Caribbean Sea tropical wave is along 64W/65W, from 20N
southward, moving westward 15 knots. Precipitation: widely
scattered moderate to isolated strong is between 60W and 74W.
Broad upper level cyclonic wind flow is in the Caribbean Sea from
the eastern parts of Honduras and the coast of Nicaragua eastward.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of Senegal
near 15N17W, to 13N30W, to the 98L low pressure center, and to
13N45W. Precipitation: widely scattered moderate to isolated
strong is from 05N to 13N between 20W and 45W. Isolated moderate
to locally strong is from 05N to 14N between 45W and 60W.

GULF OF MEXICO...

Please, read the SPECIAL FEATURES section, for details about
Hurricane Helene, that made a landfall close to Perry in Florida.

The cyclonic circulation of the hurricane has been pushing a dry
continental airmass into the western Gulf, especially from 88W
westward, allowing for generally tranquil conditions.

Moderate to near-rough seas are from 23N to 26N from 90W westward.
Moderate seas are elsewhere from 26N northward from 90W westward.
Slight seas are in the remainder of the area that is from 90W
westward. Fresh to moderate winds are in the western half of the
Gulf.

Hurricane Helene is near 29.9N 83.9W at 11 PM EDT, and is moving
north-northeast at 21 kt. Maximum sustained winds are 120 kt with
gusts to 140 kt, and the minimum central pressure is 938 mb.
Helene will move inland and weaken to a tropical storm near 33.9N
84.0W Fri morning, weaken as an extratropical cyclone near 36.9N
86.2W Fri evening, 36.8N 87.5W Sat morning, 36.9N 86.9W Sat
evening, 37.1N 86.4W Sun morning, and dissipate Sun evening. Winds
and seas will improve over the eastern Gulf waters by Fri night.
Light to gentle winds and slight seas will prevail across the
basin beginning on Sat through early next week.

CARIBBEAN SEA...

Please, refer to the TROPICAL WAVES section, for information about
the 64W/65W tropical wave.

The monsoon trough is along 10N75W in Colombia, through Nicaragua,
and into the Isthmus of Tehuantepec of southern Mexico.
Precipitation: scattered moderate to strong is within 240 nm to
the north of the monsoon trough, in Nicaragua, and in Belize; and
within 120 nm to the south of the monsoon trough from Nicaragua to
Guatemala.

Fresh to strong winds, and rough seas, cover the waters that are
from the SE Gulf, into the Yucatan Channel. Mostly moderate or
slower winds cover the remainder of the area. Slight to moderate
seas are in the remainder of the Caribbean Sea.

Hurricane Helene is centered near 29.9N 83.9W at 27/0300 UTC or
70 nm NW of Cedar Key Florida, moving NNE at 21 kt. Estimated
minimum central pressure is 938 mb. Helene will continue quickly
NE away from the basin, making landfall over the Florida Big Bend
tonight. Fresh to strong winds and rough seas will continue over
the far NW Caribbean through tonight. By Fri, gentle to moderate
winds and slight seas will prevail across the area through early
next week.

ATLANTIC OCEAN...

Please, read the SPECIAL FEATURES section, for details about the
INVEST-98L low pressure center.

Broad surface anticyclonic wind flow is from 20N northward from
50W eastward. A 1025 mb high pressure center is near 32N27W.

Moderate or slower winds, and slight to moderate seas, cover
the entire area.

Hurricane Helene is near 29.9N 83.9W at 11 PM EDT, and is moving
north-northeast at 21 kt. Maximum sustained winds are 120 kt with
gusts to 140 kt, and the minimum central pressure is 938 mb.
Helene will move inland and weaken to a tropical storm near 33.9N
84.0W Fri morning, weaken as an extratropical cyclone near 36.9N
86.2W Fri evening, 36.8N 87.5W Sat morning, 36.9N 86.9W Sat
evening, 37.1N 86.4W Sun morning, and dissipate Sun evening. Winds
and seas off the Florida east coast will improve Fri night into
Sat. Elsewhere, Tropical Storm Issac, well N of the region to the
NE of Bermuda, will continue moving away from the area, but
generate N swell that will propagate into waters N of 29N and E of
65W, producing seas near 8 ft through Fri.

$$
mt/ar