[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271744
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 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 1200 UTC surface analysis and satellite imagery through
1720 UTC.

...SPECIAL FEATURES...

Caribbean Sea Heavy Rainfall:

A deep layer trough, from eastern Hispaniola to the central
Caribbean Sea, has become stationary.
A surface trough passes through 31N70W to 26N70W, to 10N66W at
the coast of Venezuela. Precipitation: widely scattered to
scattered moderate and isolated strong is within 540 nm to the
east of the surface trough, in the Atlantic Ocean and in the
Caribbean Sea.
A 69W tropical wave is moving toward the central sections of the
Caribbean Sea. The deep layer trough and the tropical wave will
combine in order to produce numerous strong convective
precipitation in the eastern Caribbean Sea: in Puerto Rico, in
the US/UK Virgin Islands, and in the Dominican Republic, through
Friday. It is likely that excessive heavy rainfall will result
in localized flooding in parts of these islands through at least
Thursday evening. All residents in these locations should
monitor closely this developing situation. Please, stay informed
with bulletins and warnings from your local weather offices and
authorities. The deep layer trough and the tropical wave will
merge by Friday, and shift westward and weaken. An area of low
pressure is expected to form in the eastern Caribbean Sea during
the upcoming weekend. The environmental conditions are forecast
to be conducive for gradual development. It is possible that a
tropical depression may form by early next week. The feature is
forecast to move generally westward or west-northwestward
through the central Caribbean Sea.

The Southwestern Atlantic Ocean:

A trough of low pressure covers the areas that are from the
eastern Caribbean Sea northward to the southwestern Atlantic.
Disorganized rainshowers, some with thunder, continue to be
associated with the trough. A surface low pressure center is
expected to develop later today in the area of the  northern
part of the trough. The environmental conditions appear to be
marginally conducive for additional subtropical development. It
is possible that a subtropical depression may form during the
next couple of days. This weather system initially will be
moving northward. It is forecast to meander to the west or
southwest of Bermuda. The upper level winds are forecast to be
less conducive for development by this weekend. The chance of
formation into a tropical cyclone during the next 48 hours is
medium.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 47W/48W, from 18N
southward. The wave is moving westward about 15 knots.
Precipitation: scattered to numerous strong is from 13N to 17N
between 41W and 45W.

A Caribbean Sea tropical wave is along 69W, from the eastern
parts of the Dominican Republic southward, moving westward from
5 knots to 10 knots. A surface trough passes through 31N70W to
26N70W, to 10N66W at the coast of Venezuela. Precipitation:
widely scattered to scattered moderate and isolated strong is
within 540 nm to the east of the surface trough, in the Atlantic
Ocean and in the Caribbean Sea.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains Guinea near
12N15W to 10N17W. The ITCZ continues from 10N17W, to 06N22W
06N33W 08N44W 11N48W 10N60W. Precipitation: widely scattered
moderate to isolated strong is from 15N southward between 49W
and 60W, and from 10N southward from 49W eastward.

...GULF OF MEXICO...

A stationary front is in Florida from 28N82W, into the south
central Gulf of Mexico, to 23N97W.  Precipitation: disorganized
isolated moderate to locally strong spans the Gulf of Mexico.

Gentle to moderate NE to E winds, and sea heights that range
from 3 feet to 4 feet, are to the north of the front. Light to
gentle winds, and sea heights that range from 2 feet to 4 feet,
are to the southeast of the stationary front.

A stationary front stretches from just N of Tampa Bay to 23N96W.
This front will dissipate late tonight. Moderate to fresh return
flow will develop across the NW Gulf tonight into Fri morning
ahead of the next approaching cold front. This next front is
expected to push off the Texas coast late Fri afternoon and move
SE through the weekend. Strong N winds will follow the front W
of 94W through Sat afternoon, with brief gales expected across
the Veracruz area late morning Sat through
the afternoon. The front is expected to reach the Florida
Panhandle to central Bay of Campeche by Sun afternoon before
stalling and gradually dissipating.

...CARIBBEAN SEA...

Please, read the SPECIAL FEATURES section, for details about the
potential for heavy rain in the eastern Caribbean Sea through at
least Friday. A moist and unstable atmosphere will persist in
the area through the weekend, due to a persistent upper level
central Caribbean Sea trough and its interaction with a tropical
wave.

A surface trough passes through 31N70W to 26N70W, to 10N66W at
the coast of Venezuela. Precipitation: widely scattered to
scattered moderate and isolated strong is within 540 nm to the
east of the surface trough, in the Atlantic Ocean and in the
Caribbean Sea.

Light to gentle NE winds are in most of the area that is from
70W westward. Moderate to fresh E to SE winds, and sea heights
that range from 6 feet to 8 feet, are between 50W and the Lesser
Antilles.  Fresh to locally strong SE winds, and sea heights
that range from 4 feet to 7 feet in E and SE swell, are in the
eastern Caribbean Sea to the east of the tropical wave.

24-hour rainfall totals in inches, for the time period that
ended at 27/1200 UTC, according to the Pan American Temperature
and Precipitation Tables/MIATPTPAN, are: 2.50 in St. Thomas,
1.56 in Trinidad, 0.80 in San Juan in Puerto Rico.

The monsoon trough is along 10N from Colombia along 74W,
westward, beyond Panama and Costa Rica, and into the tropical NE
Pacific Ocean. Precipitation: isolated moderate to locally
strong is from 15N southward from 70W westward, in the SW corner
of the Caribbean Sea.

A deep layered upper trough N to S across the central Caribbean
will drift westward tonight through Sat then lift northward into
the Atlantic Sun. A tropical wave along 68W continues to
interact with this feature to produce scattered to numerous
thunderstorms between 63W and 68W this morning. The
tropical wave will move slowly W through the weekend. An area of
low pressure is expected to form over the eastern Caribbean Sea
this weekend, possibly related to the southern portion 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 early
next week while the disturbance moves generally westward or
west-northwestward into the central Caribbean Sea. This system
has a low chance of development in the next 48 hours and a
medium chance in the next 5 days.

...ATLANTIC OCEAN...

Please, read the SPECIAL FEATURES section, for details about the
convective precipitation that is associated with a
31N70W-to-10N66W surface trough.

A cold front passes through 31N77W to the eastern coast of
Florida near 28N80W. The rest of the front is stationary, from
Florida into the Gulf of Mexico. Precipitation: rainshowers are
possible within 240 nm to the east and southeast of the system.

A surface trough passes through 31N70W to 26N70W, to 10N66W at
the coast of Venezuela. Precipitation: widely scattered to
scattered moderate and isolated strong is within 540 nm to the
east of the surface trough, in the Atlantic Ocean and in the
Caribbean Sea.

A dissipating stationary front continues from 31N20W to 26N30W
25N40W 31N54W. The sea heights are at least 7 feet or higher
from the stationary front northward from 40W eastward. The
comparatively highest sea heights are ranging from 10 feet to 15
feet from 31N northward from 40W eastward. Light to gentle winds
are in the wake of the front. Mainly moderate E to SE winds are
between 47W and 52W. Precipitation: isolated moderate to locally
strong is within 300 nm to the south of the dissipating
stationary front.

An upper level trough passes through 31N40W to 02N50W near the
coast of South America. The upper level wind flow that is on the
eastern side of the trough is pushing broken to overcast
multilayered clouds into the area that is from 10N to the
dissipating stationary front from 40W eastward.

North swell, that is generated N of the dissipating stationary
front will produce wave heights that will range from 8 feet to
12 feet, from 29N northward from 45W eastward, through tonight.
Mainly moderate NE winds, and sea heights that range from 5 feet
to 7 feet, are from 23N southward from 40W eastward. Fresh
easterly winds, and sea heights that range from 5 feet to 8 feet,
are in the tropical Atlantic Ocean between 48W and the Lesser
Antilles.

Scattered to numerous showers and thunderstorms persist across
the Atlantic waters between 62W and 68W, supported by a deep
layered upper trough along about 70W. At the surface, a trough
of low pressure stretches from Hispaniola northward along
69W-70W. These features are expected to remain
nearly stationary through early Sat and maintain active
thunderstorms to the E. A surface low pressure system is
forecast to emerge along the northern portion of the trough axis
later today or tonight, and environmental conditions appear
marginally conducive for some subtropical development. A
subtropical depression could form during the next couple of days
while the system moves northward, then meanders to the west or
southwest of Bermuda. Over this weekend, upper-level winds are
forecast to become less conducive for development. This system
has a medium chance of development in the next 48 hours and 5
days. Associated large NE swell will impact the northern waters
W of 70W Fri night through the weekend.

$$
mt/ar
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