[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270552
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Thu Oct 27 2022

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
0515 UTC.

...SPECIAL FEATURES...

Southwestern Atlantic:
A trough of low pressure stretching from the eastern Caribbean Sea
northward to the southwestern Atlantic continues to produce a
broad area of disorganized showers and thunderstorms. The northern
part of this trough axis is expected to result in the formation of
a surface cyclone, and environmental conditions appear somewhat
conducive for subtropical development of this system thereafter. A
subtropical depression could form while the system moves northward
during the next couple of days. The system is then forecast to
meander over the subtropical western Atlantic to the west or
southwest of Bermuda as upper-level winds are forecast to become
less conducive for development by the end of the weekend. This
system has a medium chance of becoming a tropical cyclone during
the next 48 hours. Please refer to the latest NHC Tropical Weather
Outlook at www.hurricanes.gov for more details.

Caribbean Sea Heavy Rainfall:
A deep-layer trough over the central Caribbean is drifting
eastward. In addition, a tropical wave, with axis along 67W/68W is
moving westward across the eastern Caribbean. These two systems
will combine to produce numerous showers and thunderstorms over
the eastern Caribbean Sea, including Puerto Rico, the US/UK Virgin
Islands and the Dominican Republic. Excessive heavy rainfall will
likely result in localized flooding across portions of Puerto
Rico, the US/UK Virgin Islands, and eastern Hispaniola through at
least Thu evening. Residents in these locations should monitor
this developing situation closely and stay informed with their
local weather offices and authorities. In addition, an area of low
pressure is expected to form over the eastern Caribbean Sea this
weekend, possibly related to the southern part of an existing
trough of low pressure over the area. Thereafter, environmental
conditions are forecast to be conducive for gradual development,
and a tropical depression could form by early next week while the
disturbance moves generally westward or west-northwestward into
the central Caribbean Sea.

...TROPICAL WAVES...

A tropical wave has its axis along 45W from 04N to 18N. It is
moving westward near 15 kt. Scattered moderate to isolated strong
convection is ahead of the wave axis from 09N-11N between 45W and
49W. Abundant moisture with embedded showers and isolated
thunderstorms follows the wave. This activity is also ahead of an
upper-level trough. Moderate to locally fresh NE to E winds are
on either side of the wave axis based on a recent scatterometer
pass.

Another tropical wave is over the eastern Caribbean with axis
along 67W/68W from 09N to 20N. It is moving westward at 5-10 kt.
The wave is interacting with a deep-layer trough. As a result, a
large area of moderate to strong convection is between the wave
and the Lesser Antilles. A diffluent pattern aloft on the east
side of the deep-layer trough is helping to sustain this
convective activity.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coastal plains of Guinea
near 10N14W to 08N19W. The ITCZ continues from 08N19W to 06N30W
to 08N42W to 10N60W. A large area of moderate to isolated strong
convection is observed from the ITCZ north to 19N and between
30W-40W. Numerous moderate to isolated strong convection is noted
over parts of Liberia and Sierra Leone, and from 05N-09N between
17W and 24W.

...GULF OF MEXICO...

A cold front stretches from N Florida near 29N82.5W to 22N93W
where it becomes stationary and continues S over the central Bay
of Campeche. No deep convection is noted with this front. Gentle
to moderate northerly winds follow the front with seas of 3-5 ft.
Light to gentle winds and wave heights of 2-4 ft are noted ahead
of the front.

For the forecast, the aforementioned cold front will stall tonight
just N of the Tampa Bay area then dissipate Thu night. Moderate
to fresh return flow will develop across the NW Gulf Thu night
into Fri morning ahead of the next approaching cold front. This
next cold front is expected to push off the Texas coast on Fri
afternoon and move eastward through the weekend. N winds behind
the front could increase to gale-force near Veracruz on Sat
morning for a few hours. The front will reach the eastern Gulf by
Sun.

...CARIBBEAN SEA...

Please read the Special Features section for details about the
potential for heavy rain in the eastern Caribbean Sea through
at least Fri. A moist and unstable atmosphere will persist across
the area due to the interaction of a tropical wave and a deep-
layer trough.

Light to gentle trade winds are over most of the basin. Moderate
to fresh E to SE winds and seas in the 6-8 ft range prevail just
E of the Lesser Antilles to about 55W. Wave heights of 4-6 ft in
east swell are to the east of the tropical wave. Seas of 2-4 ft
are elsewhere in the basin.

For the forecast, a weak pressure gradient across the region will
maintain gentle to moderate NE to E winds across the basin W of
70W through Fri. A deep layer upper trough extending N to S across
the central Caribbean will remain stationary over the area through
Sun then gradually lift northward early next week. A tropical
wave along 67W/68W is presently interacting with this feature to
produce scattered to numerous thunderstorms E of the wave axis.
The tropical wave will move slowly W through Sat and gradually
merge with the upper trough along 70W.

...ATLANTIC OCEAN...

Please see the Special Features section for details about
convection associated with a trough of low pressure stretching
from the eastern Caribbean Sea northward to the southwestern
Atlantic.

A dissipating stationary front extends from near 31N21W to
26N35W to 24N40W to 31N52W. Light to gentle winds are noted in the
wake of the front with an area of mainly moderate E to SE winds
between 47W-52W. A 1018 mb high pressure center is just to the
north of the Canary Islands near 29N15W. North swell will
produce wave heights of 8-12 ft roughly to the waters north of 29N
and east of 45W through tonight. Wave heights of 5-8 ft in the
tropical Atlantic are between 35W and the Lesser Antilles.

For the forecast, scattered to numerous showers and thunderstorms
persist across the Atlantic waters between 60W-70W. This convective
activity is associated with a deep layer upper-level trough. At
the surface, a trough is analyzed along 70W stretching from
Hispaniola to near 29N70W. Environmental conditions appear
conducive for some gradual subtropical development of this system,
and a subtropical depression could form while it drifts northward
during the next couple of days.

$$
GR
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