[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111050
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Oct 11 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 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...SPECIAL FEATURES...

N Gulf of Mexico and W Atlantic Gale Warning: As of 0600 UTC, a
1003 mb low pressure is located near 23.5N95.5W in the SW Gulf of
Mexico along the western end of an old frontal boundary that has
begun to lift northward in recent hours. The front extends from SW
Florida to 27N90W to the low center. The front and low pres will
lift northward today, reaching along 29N-30N. The low pres is
expected to strengthen along the front this morning over the NW
Gulf, and move eastward across the N central and NE Gulf this
afternoon through evening, then inland across N Florida Wed
night. Scattered to numerous strong thunderstorms and strong to
gale force winds will accompany this low pressure system and
frontal boundary across the northern Gulf late tonight through Wed
night. Seas are expected to peak near 13 ft this evening. The low
will then emerge across the W Atlc early Thu, bringing strong to
gale force winds east of northern and central Florida Thu night,
then move E of 75W Thu night, and across the NE waters Fri through
early Sat. Scattered thunderstorms with large and confused seas
are expected to accompany this low pressure system. Seas are
expected to peak around 15 ft Fri. Please read the latest HIGH
SEAS FORECAST issued by the National Hurricane Center at website -
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml.

Newly upgraded Tropical Storm Sean is located across the eastern
tropical Atlantic near near 10.3N 33.1W at 5 AM EDT, moving
west-northwest at 11 kt. Maximum sustained winds are 35 kt with
gusts to 45 kt. Minimum central pressure is 1006 mb. Numerous
showers and thunderstorms are occurring from 09N to 13N and
between 30W and 38W. Peak seas near the center are to 12 ft. A
west-northwestward to northwestward motion is forecast during the
next few days. Some minor strengthening is possible during the
next day or so, before Sean is expected to encounter strong upper
level wind shear, which will likely lead to a weakening trend.

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
Tropical Depression Nineteen NHC Forecast/Advisory and Public
Advisory at www.hurricanes.gov for more details.

...TROPICAL WAVES...

A tropical wave in the far eastern Atlantic along 20W, south of
17N. The wave is moving westward at 10 kt. Scattered moderate to
strong convection is seen on satellite imagery from 08N to 14N
and east of 23W.

A western Caribbean Sea tropical wave has its axis along 86W,
south of 21N, moving westward at 10-15 kt. The wave extends
across Honduras and western Nicaragua into the eastern Pacific
waters. Scattered showers and isolated thunderstorms are noted
near the northern portion of the wave, affecting the Cayman
Islands and the southwest coastal waters of Cuba.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of
Senegal near 14N16.5W and continues southwestward to 08.5N23W to
10N28W. The ITCZ extends from 09N42W to 11N53W. A few showers and
mild thunderstorms are present near the ITCZ.

...GULF OF MEXICO...

Please read the Special Features section for details about the
Gale Warning in the northern Gulf.

A weak high pressure center has shifted northward from the Big
Bend area of Florida into SW Georgia, and extends a weak ridge
westward across the northern Gulf of Mexico. Strong low level
southerly flow across the south central Gulf has lifted the
stationary front northward in recent hours to along 26N-27N. At
the surface, southerly winds have increased to near 20 kt south
of the front between the low pressure center at 95.5W and 87W.
Seas are building to 4-7 ft there. Bands of moderate to strong
convection have developed across the central Gulf from 23N to 28N
between 88W and 94W. E of 87W, moderate E to SE winds prevail,
with seas 2-3 ft.

For the forecast, the front and low pres will continue to lift
northward today, reaching along 29N-30N. The low pres is expected
to strengthen along the front this morning over the NW Gulf, and
move E-NE across the N central and NE Gulf this afternoon and
evening, then inland across N Florida tonight. Scattered to
numerous strong thunderstorms and strong to gale force winds will
accompany this low pressure system and frontal boundary across the
northern Gulf through tonight. Seas are expected to peak at 12-13
ft north of the front this afternoon. High pressure across the
Atlantic will build modestly westward into the eastern Gulf Fri
through early Sat, before the next cold front moves into the NW
Gulf Sat morning and across the entire basin by Sun evening.

...CARIBBEAN SEA...

A surface trough extending across western Cuba to the NW
Caribbean Sea has weakened in recent hours. However, favorable
upper level dynamics and abundant moisture are supporting
scattered moderate strong convection north of 20N and between 80W
and 85W. Scattered moderate to strong convection is also seen
off NW Colombia. The remainder of the Caribbean is influenced by
a subtropical ridge located over the Atlantic north of the Greater
Antilles.

The pressure gradient between the aforementioned subtropical ridge
and lower pressures in northern South America sustain fresh easterly
trade winds in the south-central Caribbean. The strongest winds
are occurring near and in the Gulf of Venezuela. Seas of 5-7 ft
are present in the south-central Caribbean. Elsewhere moderate to
fresh easterly winds prevail across the basin E of 80W. Seas in
these waters are 3-5 ft. W of 80W, moderate to fresh southerly
flow has begun to open up into the eastern Gulf of Mexico. Seas
of 3-4 ft are prevalent.

For the forecast, the weak ridge across the Atlantic will shift
slightly W-NW into Thu morning. Moderate to fresh E trade winds
will prevail across the eastern and central Caribbean through Thu
then gradually diminish into the weekend. Scattered thunderstorms
will prevail across the NW basin today NE of the tropical wave
currently along 86W. Fresh SE to S winds will develop across the
outer Gulf of Honduras and NW Caribbean today and become strong
tonight through Thu night as low pressure moves eastward across
the northern Gulf of Mexico.

...ATLANTIC OCEAN...

Please read the Special Features section for details about the
Gale Warning in the SW tropical Atlantic and Tropical Depression
Nineteen in the eastern Atlantic.

A stationary front is draped across the SW tropical Atlantic,
extending from 31N71W to just N of the NW Bahamas and then across
southern Florida. A pre-frontal trough is analyzed within 180 nm
of the frontal boundary, supporting scattered showers and isolated
thunderstorms, also affecting the waters offshore of central
Bahamas. Fresh to strong winds are occurring in association with
the strongest convection. Elsewhere west of 60W, moderate or
weaker winds and moderate seas prevail.

Another area of showers and thunderstorms is noted north of 26N
and between 49W and 57W. Farther east, a surface trough enters
the basin near 31N39W and extends to 23N50W. Scattered showers
and thunderstorms are present north of 25N and east of the trough
to 28N. Moderate to locally fresh southerly winds are evident
north of 24N and between 29W and 44W. Seas in these waters are 6-9
ft in N swell. In the rest of the basin, a weak high pressure
pattern supports moderate or weaker trade winds and moderate
seas in northerly swell.

For the forecast, weak high pressure N of the Leeward Islands will
shift W across the remainder of the Bahamas. Low pressure along a
Gulf of Mexico front is expected to move eastward across N
Florida tonight, then continue eastward and emerge across the W
Atlc, bringing strong to gale force winds east of northern and
central Florida Thu, then move E of 75W Thu night, and across the
NE waters Fri through early Sat. Scattered thunderstorms with
large and confused seas are expected to accompany this low
pressure system.

$$
Stripling
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