[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 012300
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Tue Nov 2 2021

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
2150 UTC.

...SPECIAL FEATURES...

Tropical Storm Wanda is centered near 34.2N 42.2W at 2100 UTC, or
770 nm WSW of the Azores moving ENE at 6 kt. Estimated minimum
central pressure is 996 mb. Maximum sustained wind speed is 40 kt
with gusts to 50 kt. Scattered moderate isolated strong convection
is seen within 150 nm across the NE quadrant of Wanda as vertical
wind shear has diminished today. This has allow Wanda to transition
from a subtropical cyclone to a tropical cyclone. A very complex
steering flow pattern is expected to prevail in the region near
Wanda, and this will likely yield a zig-zag motion across the
north-central Atlantic during the next several days, resulting in
a net eastward track toward the western Azores. Some slight
increase in the strength of Wanda is possible during the next 48
hours as wind shear remains weak. Please see the latest Wanda NHC
Forecast/Advisory and Public Advisory at www.hurricanes.gov and
the latest High Seas Forecast issued by the Ocean Prediction
Center at
https://ocean.weather.gov/mobile/mobile_product.php?id=NFDHSFAT1
for more details.

...TROPICAL WAVES...

The weak tropical wave is analyzed along 42W, from 08N to 18N,
moving W around 10 kt. The wave is embedded in a dry airmass that
is suppressing the development of showers and thunderstorms. No
significant clouds or convection is seen near the wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of
Sierra Leone near 09N13W to 07N16W. The ITCZ then continues from
07N16W to 05N21W to 06.5N28W. Scattered moderate convection is
from 01N to 05N between 10W and 20W.

GULF OF MEXICO...

A ridge prevails across the Gulf waters this afternoon producing
light to gentle winds and seas generally in the 1-3 ft range. A
band of high clouds extends from the Tampico, Mexico area
northeastward, to coastal zones from the mouth of the Mississippi
River to the Florida Big Bend. Otherwise, only widely scattered
narrow bands of low clouds prevail across the basin as stable
atmospheric conditions prevail.

Weak high pressure north of the area will maintain light to gentle
easterly breezes and slight seas through Tue. Winds will increase
to moderate Wed over the northern half of the Gulf, ahead of a
cold front expected to move into the northwest Gulf Wed night
into Thu. The front will reach from near Tampa, Florida to the W
Bay of Campeche Fri morning and fresh to strong NE winds will
develop over the offshore waters between the Florida Big Bend and
the front. The front will exit the basin Fri night.

CARIBBEAN SEA...

A dissipating frontal boundary extends from near Cabo Cruz in
eastern Cuba to near the Honduras-Nicaragua border. A 1009 mb low
pressure is analyzed over the SW Caribbean near 10.5N81W.
Scattered showers and isolated thunderstorms are along the
frontal boundary while clusters of moderate to strong
thunderstorms are noted S of 14N and W of 81W. This convective
activity is currently affecting extreme NW Panama, and extends
well inland across the coastal zones of Costa Rica and eastern
Nicaragua. A late morning scatterometer pass showed the cyclonic
circulation related to the low center, with fresh to locally
strong winds in the NE quadrant of the low. Fresh to strong winds
are also seen near the convective activity associated with this
low. Fresh northerly winds are in the wake of the front in the lee
of eastern Cuba. Moderate to locally fresh trades are near the
coast of Colombia. Seas are 2-4 ft across the basin, with the
exception of 4-7 ft near the aforementioned low pressure, and
just W of the frontal boundary S of 18N.

The dissipating frontal remnants will slowly shift westward
through Wed, supporting the continuation of showers and fresh NE
winds in the NW Caribbean. Moderate to fresh NE winds over
Nicaragua adjacent waters will diminish Tue as the low pressure
over the SW Caribbean weakens into a surface trough. Otherwise, a
weak pressure gradient will support mainly gentle to moderate
trade winds across the central and E basin through Sat night.

ATLANTIC OCEAN...

A cold front extends from 31N61W to far eastern Cuba near 21N75W.
Scattered showers and a few thunderstorms are along the front
south of 24N. Light to gentle winds are on either side of the
front. A 1018 high pressure is ahead of the front near 23.5N65W.
A surface trough stretches from the eastern side of Wanda through
31N42W to 24N45W to 21N55W. Satellite derived wind data clearly
indicate the wind shift associated with the trough as well as
fresh to strong southerly winds N of 26N E of the trough to about
31W. The pressure gradient between this trough and a high pressure
of 1024 mb located W of the Madeira Islands supports these winds.
Scattered showers and thunderstorms are ahead of trough mainly N
of 29N.

Over the tropical Atlantic, 1010 mb low pressure is located near
14.5N33.5W or several hundred miles west-southwest of the Cabo
Verde Islands. This system continues to produce disorganized
shower and thunderstorm activity mainly within 360 nm E through NE
of the low. Visible satellite imagery today showed a well defined
swirl of low clouds associated with the low center. This system
is moving northwestward into a region of less conducive upper-
level winds, and the chances of tropical cyclone development are
decreasing.

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Ash emission
is visible on satellite data. Medium to high volcanic ash
concentration over volcano and vicinity. Marine and aviation
interests should monitor this ongoing situation by reading the
Volcanic Ash Advisory issued by Meteo- France at website
http://vaac.meteo.fr/volcanoes/la-palma/.

West of 65W, look for the frontal boundary to stall from 25N65W
to eastern Cuba this evening, then dissipate Tue morning. High
pressure building behind the front will support gentle to moderate
NE to E winds through mid week, except occasionally pulsing to
fresh off Hispaniola mainly at night. Looking ahead, fresh to
strong N to NE winds will follow a front moving into the waters
off northeast Florida late Fri.

$$
Stripling
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