[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 282328
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Tue Aug 29 2023

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
2300 UTC.

...SPECIAL FEATURES...

Major Hurricane Franklin is centered near 28.5N 71.0W at 28/2100 UTC
or 420 nm N of Grand Turk Island, moving N at 8 kt. Estimated
minimum central pressure is 937 mb. Maximum sustained wind speed
is 125 kt with gusts to 150 kt. Peak seas are currently around 35
ft. A well-defined eye is apparent in satellite imagery and
numerous moderate to strong convection is evident within 75 nm of
the center with numerous moderate elsewhere within 150 nm of the
center. The northward to north-northeastward motion with a
slightly faster forward speed is expected during the next few
days. On the forecast track, the center of Franklin is expected to
pass well to the west of Bermuda on Wednesday. Franklin is a
category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.
Additional strengthening is possible, but gradual weakening is
expected to begin late Tuesday. Swells, life-threatening surf and
rip currents generated by Franklin are already affecting Bermuda
and the coast of the southeast United States. These conditions are
expected to spread northward along the east coast of the United
States and Atlantic Canada during the next couple of days.

Tropical Storm Idalia is centered near 21.4N 85.1W at 28/2100
UTC or 30 nm SSW of the western tip of Cuba, moving N at 7 kt.
Estimated minimum central pressure is 987 mb. Maximum sustained
wind speed is 60 kt with gusts to 75 kt. Peak seas are currently
around 24 ft. Numerous moderate to strong convection is evident
within 135 nm in the SE semicircle and 45 nm in the NW semicircle.
Scattered moderate convection is evident elsewhere within 210 nm
in the SE semicircle and 90 nm in the NW semicircle. Additional
deep convection is noted in a bands covering the NW Caribbean Sea,
west of 80W. A northward motion is expected through tonight,
followed by a faster north-northeast motion on Tuesday and
Wednesday. On the forecast track, the center of Idalia is forecast
to pass near or over western Cuba tonight, over the eastern Gulf
of Mexico on Tuesday, and reach the Gulf coast of Florida within
the Hurricane Warning area on Wednesday. Rapid strengthening is
predicted during the next day or so. Idalia is forecast to become
a hurricane this evening or tonight, and become a major hurricane
by late Tuesday or Tuesday night.

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
Franklin and Idalia NHC Forecasts/Advisories and Public Advisories
at www.hurricanes.gov for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 37W, south
of 17N, moving westward at 15-20 kt. A few showers are noted near
the southern portion of the trough axis.

A central Atlantic tropical wave has its axis along 55W, south of
17N, moving westward at 10-15 kt. Scattered showers are noted in
within 60 nm on either side of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic near 20N17W and continues
southwestward to 07N42W. Scattered moderate convection is evident
from 04N to 10N and east of 30W.

...GULF OF MEXICO...

Please read the SPECIAL FEATURES section for details about
Tropical Storm Idalia, currently over the Yucatan Channel.

A stationary front is draped across the NW Gulf of Mexico
producing a few showers. Meanwhile, a surface trough is analyzed
in the eastern Gulf of Mexico generating scattered showers and
isolated thunderstorms. Outer rainbands of Idalia are noted in
latest satellite imagery off SW Florida. To the west, another
surface trough is analyzed in the Bay of Campeche enhancing scattered
shower activity. Moderate or weaker winds and slight seas prevail
across most of the Gulf, except for the SE Gulf where Idalia is
inducing stronger winds and higher seas.

For the forecast, Tropical Storm Idalia will strengthen to a
hurricane near 22.7N 85.2W Tue morning, move to 24.9N 85.0W Tue
afternoon, 27.6N 84.4W Wed morning, inland to 30.4N 82.9W Wed
afternoon, and weaken to a tropical storm near 32.7N 80.4W Thu
morning. High pressure and improving conditions will arrive in the
wake of Idalia late in the week.

...CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details about
Tropical Storm Idalia, currently over the Yucatan Channel.

Outside of Idalia, high pressure aloft in the eastern and central
Caribbean results in subsidence, keeping the region devoid of any
deep convection. Moderate to fresh easterly trade winds were
captured by a recent scatterometer satellite pass in the eastern
and central Caribbean, while light to gentle winds prevail in the
SW Caribbean. Seas are slight to moderate in the eastern and
central Caribbean and slight in the SW Caribbean.

For the forecast, Tropical Storm Idalia will strengthen to a
hurricane over the Gulf of Mexico near 22.7N 85.2W Tue morning. As
Idalia moves farther N into the Gulf of Mexico on Tue, conditions
will improve in the NW Caribbean. High pressure will build
westward across the western Atlantic through Thu as Hurricane
Franklin lifts north of the region. This will lead to moderate to
fresh trade winds in the eastern Caribbean by tonight, then in the
central Caribbean by Tue, locally strong there.

...ATLANTIC OCEAN...

Please read the SPECIAL FEATURES section for details about
Hurricane Franklin and Tropical Storm Idalia.

Outside of Franklin, a 1032 mb subtropical ridge positioned a few
hundred miles to the northeast of the Azores dominates the
eastern and central Atlantic. A couple of surface troughs are
noted in the central Atlantic, producing scattered moderate
convection north of 20N and between 46W and 64W. Latest
satellite-derived wind data suggests that fresh to strong winds
are present with the strongest convection. Moderate or weaker
winds and slight to moderate seas are prevalent west of 25W.

The pressure gradient between the aforementioned high pressure and
lower pressures in NW Africa result in fresh to near gale
northerly winds east of 25W and north of 16N. Seas in these
waters are 6-10 ft. Elsewhere, moderate or weaker winds and slight
to moderate seas prevail.

For the forecast W of 55W, Hurricane Franklin is near 28.5N 71.0W
at 5 PM EDT, and is moving north at 8 kt. Maximum sustained winds are
125 kt with gusts to 150 kt, and the minimum central pressure is
937 mb. Franklin will move to 29.7N 71.1W Tue morning, 31.3N 70.3W
Tue afternoon, and will be N of area near 33.0N 68.8W Wed
morning. Expect increasing winds and building seas E of Florida on
Tue as Idalia moves across the Eastern Gulf of Mexico. Tropical
Storm Idalia will strengthen to a hurricane near 22.7N 85.2W Tue
morning, move to 24.9N 85.0W Tue afternoon, 27.6N 84.4W Wed
morning, inland to 30.4N 82.9W Wed afternoon, move inland and
weaken to a tropical storm near 32.7N 80.4W Thu morning, and 34.0N
76.8W Thu afternoon. Idalia will change little in intensity as it
moves to near 34.1N 71.4W by Fri afternoon.

$$
ERA
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