[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291716
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sun Oct 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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...SPECIAL FEATURES...

Southwestern Atlantic Ocean (AL96): Showers and thunderstorms
associated with an area of low pressure located a couple of
hundred miles east of the southeastern Bahamas, near 23N70W with a
central pressure around 1007 mb, continue to show signs of
organization. Scattered moderate convection is noted from 18N to
26N between 62W and 70W. Seas are up to 13 ft near the low. A
short-lived tropical depression or storm is likely to form later
today or tonight while the system moves WNW. By Tuesday, however,
strong upper-level winds and dry air should end the chances of
further development. An Air Force reconnaissance aircraft is
scheduled to investigate the system later today. The chance of
development over the next 48 hours is high. Please read the latest
Tropical Weather Outlook at hurricanes.gov for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Senegal near 13N17W
to 10N20W. The ITCZ extends from 10N20W to 05N37W to 08N54W.
Scattered moderate convection is noted from 02N to 10N between 18W
and 42W. A trough is located north of the ITCZ from 15N46W to
10N53W with scattered moderate to isolated strong convection from
09N to 15N between 40W and 54W.

GULF OF MEXICO...

The subtropical ridge continues to extend across the Gulf of
Mexico. This is giving way to benign conditions across the basin
with no significant convection noted at this time. Surface
observations and the latest scatterometer shows gentle to moderate
winds are noted across the basin. Buoys also show seas are
ranging 3 to 4 ft.

For the forecast, the high pressure centered across the middle
Atlantic coastal states extends westward to N Louisiana and will
continue to support fresh to locally strong winds in the southeast
and south central Gulf through today. Gentle NE winds are
expected by Mon as the pressure gradient weakens and high pressure
settles southward along about 31N. A strong cold front will enter
the NW Gulf Mon morning, and move SE across the entire basin by
Wed evening. This front will bring gale force winds and quickly
build seas over the western Gulf beginning Mon thru Wed night.

CARIBBEAN SEA

Please read the SPECIAL FEATURES section for more information on
Invest 96L which is located north of the Dominican Republic. A
trough extends south of this low to the central Caribbean, just
south of the Dominican Republic. Heavy rainfall from this system
along the trough could continue across the NE Caribbean through
the next week, which could worsen any ongoing flooding hazards.

The eastern Pacific monsoon trough extends from the central
Caribbean to a 1008 mb low near 14N76W to the coast of southern
Nicaragua. Scattered moderate convection is noted from 10N to 18N
between 7W and 84W. Moderate southerly winds are noted south of
the monsoon trough and the low pressure. Gradual development is
possible while the system moves generally westward at 10 to 15 kt.
The chances of formation are low within 48 hours and low in 7
days.

Outside of Invest 96L and the monsoon trough and low pressure in
the central Caribbean, isolated thunderstorms are noted in the
Gulf of Honduras. Outside of that, no significant convection is
noted across the NW Caribbean. The pressure gradient across the NW
Caribbean and SE U.S. is weakening, which is leading to moderate
to locally fresh winds in the NW portion of the basin. Light to
gentle winds are noted across the rest of the basin based on the
latest scatterometer data. Seas range 3 to 5 ft across the
Caribbean.

For the forecast, the elongated low pressure extending from the
nearby Atlantic along 70W and trough shift W-NW and into the W
central Caribbean through early this week, with winds diminishing
across the NW Caribbean later today. Scattered strong
thunderstorms will shift westward with the trough through Mon.
Large N-NE swells across the W Atlantic will continue to move
through the NE Caribbean Passages through today. A strong cold
front will enter the NW Caribbean Wed.

ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section above for information on
Invest 96L positioned north of the Dominican Republic.

Surface ridging extends across the southwest N Atlantic anchored
by high pressure in the SE U.S. The pressure gradient between this
high pres and Invest 96L is leading to moderate to fresh winds
off the Florida and Bahamas coast. Buoys and altimeter data show
seas are ranging 6 to 9 ft. Seas up to 8 ft extend as far south as
the Leeward Islands.

East of Invest 96L, surface ridging extends across the central
and eastern Atlantic anchored by a 1017 mb high pres near 24N41W.
Under the influence of this high, scatterometer data shows gentle
to moderate winds with seas ranging 5 to 8 ft. South of Post-
Tropical Cyclone Tammy, seas ranging 8 to 12 ft are noted from 29N
northward between 49W and 57W. In the eastern Atlantic, a cold
front extends from 31N23W to 29N35W then becomes stationary from
that point to 30N38W. Moderate to locally fresh N winds are noted
N of the front, and moderate SW winds S of the front. Light to
gentle winds are noted around the stationary front. Seas range 8
to 9 ft near the front. Light to gentle winds are noted across the
rest of the eastern Atlantic with seas 6 to 10 ft per altimeter
data.

For the forecast W of 55W, Invest 96L will shift NW through Mon
before weakening. A short-lived tropical depression or storm could
form later today. By Monday, however, strong upper-level winds
and dry air should end the chances of further development. Expect
strong winds to near gale-force near the low center and numerous
strong thunderstorms along and E of the trough extending into the
NE Caribbean through tonight. Elsewhere, high pressure centered
across the middle Atlantic states extends eastward and to the N of
the trough and low, while Post-Tropical Cyclone Tammy is near 32N
53.5W at 11 AM EDT, moving E-SE east at 15 kt. A strong cold
front will enter the NW waters Wed.

$$
AReinhart
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