[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 310008
TWDAT

Tropical Weather Discussion...Updated
NWS National Hurricane Center Miami FL
0005 UTC Thu Aug 31 2023

Updated for 0000 UTC advisory

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 1800 UTC surface analysis and satellite imagery through
2230 UTC.

...SPECIAL FEATURES...

Tropical Storm Idalia is centered near 32.7N 80.9W at 30/0000
UTC or 50 nm W of Charleston South Carolina, moving NE at 18 kt.
Estimated minimum central pressure is 985 mb. Maximum sustained
wind speed is 55 kt with gusts to 65 kt.  Numerous
moderate isolated strong convection is within 270 nm of the center
in the NE semicircle, including over far eastern Georgia, much of
South Carolina and SE North Carolina. Scattered moderate
convection is within 90 nm SW semicircle. Scattered moderate
convection is elsewhere within 420 nm NE quadrant and 330 nm NW
quadrant. Scattered thunderstorms are also noted farther south
over Florida, over the Atlantic to the north of the NW Bahamas,
and over the eastern Gulf of Mexico in a line extending from
Sarasota southwestward to 24N87W. Peak seas are 13 ft offshore
the Florida/Georgia border area, but are forecast to quickly
increase this evening. Tropical storm force winds are currently
spreading across the waters east of northern Florida. A
northeastward motion is expected to continue through tonight. A
generally eastward motion is forecast to begin on Thursday and
continue through Saturday. On the forecast track, the center of
Idalia will move near or along the coasts of Georgia and South
Carolina through tonight, and then just offshore the coast of
North Carolina on Thursday. Idalia will then move eastward over
the western Atlantic into the weekend. Swells generated by Idalia
over the eastern and central Gulf of Mexico will subside tonight
and Thursday. Swells will affect the southeastern U.S. coast
during the next few days. These swells are likely to cause life-
threatening surf and rip current conditions.

Hurricane Franklin is centered near 34.4N 65.2W at 30/0000 UTC
or 120 nm N of Bermuda, moving ENE at 12 kt. Estimated minimum
central pressure is 961 mb. Maximum sustained wind speed is 90
kt with gusts to 110 kt.  Seas of 8-12 ft are still affecting Atlantic
waters from 28N-31N between 61W-71W. An east-northwestward motion
is expected to begin tonight and continue through Friday. On the
forecast track, the center of Franklin is expected to pass to the
north of Bermuda through this evening. Life-threatening surf and
rip current conditions are affecting Bermuda and the east coast of
the United States. These conditions are expected to continue
during the next day or two. For more details, refer to the High
Seas Forecast issued by the Ocean Prediction Center at
ocean.weather.gov/shtml/NFDHSFAT1.php

Tropical Depression Eleven is centered near 28.5N 52.3W at
30/2100 UTC or 685 nm ESE of Bermuda, moving N at 2 kt. Estimated
minimum central pressure is 1014 mb. Maximum sustained wind speed
is 30 kt with gusts to 40 kt. Peak seas are currently 9 ft.
Scattered moderate to strong convection is noted within 180 nm of
the center in the SE semicircle. The system is expected to become
a remnant low within the next day or so.

Invest AL94 in the eastern Atlantic: Low pressure of 1007 mb is
located along a tropical wave near the Cabo Verde Islands at
15.5N24W. Winds are currently to 25 kt with seas to 8 ft.
Scattered moderate to strong convection is evident from 10N to 18N
and E of 30W. Environmental conditions appear conducive for
gradual development of this system, and a tropical depression is
likely to form later this week while the system moves west-
northwestward to northwestward across the eastern tropical
Atlantic. This system has a medium chance of tropical cyclone
formation within the next 48 hours and 7 days. Please refer to
the latest Tropical Weather Outlook at https://www.hurricanes.gov
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 for the latest on
Franklin, Idalia and T.D. Eleven. For NHC Forecasts/Advisories
and Public Advisories on these systems, see www.hurricanes.gov

...TROPICAL WAVES...

A tropical wave is in the Atlantic along 55W, S of 17N, moving W
at 15 kt. Scattered moderate convection is from 08N to 12N
between 47W and 56W.

A tropical wave is in the Caribbean along 71/72W and S of 19N,
moving W at 15 kt. Scattered showers and isolated tstorms are
along and within 270 nm E of the wave axis from 13N to 16N.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the eastern Atlantic from the coast of
Africa near 14N17W to AL94 near 15.5N24W to 10N36W. The ITCZ
continues from 10N36W to 08N44W to 9.5N53.5W. No significant
additional convection is noted, other than the convection
mentioned in the sections above.

...GULF OF MEXICO...

With Tropical Storm Idalia nearing Savannah, Georgia, winds have
diminished to the 15-25 kt range over the eastern Gulf. Seas have
subsided to 7-8 ft just to the west of Florida. To the west of
87W and north of 23N, gentle to moderate winds prevail along with
seas of 4-7 ft in E swell. In the far SW Gulf, gentle to moderate
winds with 2-4 ft seas prevail. Isolated showers and tstorms are
noted over portions of the central and south-central Gulf.
Thunderstorms in the eastern Gulf were mentioned above in the
Idalia special features paragraph.

For the forecast, winds and seas across the Gulf will continue to
diminish tonight. High pressure and improved conditions will
arrive Thu and persist through the upcoming weekend.

...CARIBBEAN SEA...

Refer to the Tropical Waves section for details on a tropical
wave in the central Caribbean.

Gentle to moderate SE-S winds and 2-4 ft seas cover the NW
Caribbean. Moderate to fresh trades are E of 80W, except for fresh
to strong in the south-central Caribbean. Seas are 4-7 ft east of
80W.

For the forecast, fresh to strong trades will pulse in the
central Caribbean through Fri night. Gentle to moderate winds will
prevail in the western Caribbean with moderate to fresh winds in
the eastern Caribbean. Trades will weaken this weekend as the
pressure gradient relaxes.

...ATLANTIC OCEAN...

Please, read the SPECIAL FEATURES section for details about
Hurricane Franklin, Tropical Storm Idalia, Tropical Depression
Eleven, and Invest AL94.

Other than those four systems, a 1014 mb low pressure area, the
remnants of Gert, is located near 27N59W. Scattered moderate
convection is noted from 23N to 29N between 57W and 63W. Winds
are likely around 25 kt. Seas are currently around 5 ft.
Elsewhere, a ridge extends from near 26N46W through 23N65W to the
central Bahamas. Gentle to moderate winds dominate the remainder
of the open waters, along with seas of 3-7 ft.

For the forecast W of 55W, Tropical Storm Idalia will move to near
33.4N 79.3W around 2am EDT Thu morning, 34.1N 75.7W Thu
afternoon, 32.8N 69.7W Fri afternoon, 31.7N 67.3W Sat afternoon
and 32.3N 65.1W Sun afternoon. Idalia will spread tropical storm
force winds and seas 12-16 ft through early Thu morning north of
30N and west of 74W. Winds over 25 kt and seas 8-16 ft will spread
across the waters north of 28N through Thu as Idalia moves E,
then north of 29N between 61W-77W Fri through Sun. Meanwhile, the
8-12 ft seas that are still affecting Atlantic waters from 28N-31N
between 61W-71W due to Franklin will diminish to 8 to 9 ft Thu as
these conditions move northeastward to N of 30N between 55W-63W
Thu morning.

$$
Hagen/jl
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