[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 021654
TWDAT

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

...SPECIAL FEATURES...

Wanda is moving northward over the northern Atlantic. At 02/1500
UTC, Tropical Storm Wanda is centered near 35.6N 40.6W or 670 nm
W of the Azores moving N at 8 kt. Estimated minimum central
pressure is 992 mb. Maximum sustained wind speed is 45 kt with
gusts to 55 kt. On the forecast track, a turn toward the north-
northeast is expected this afternoon or evening, followed by a
northeastward motion tonight and Wednesday. Little change in
strength is forecast during the next couple of days. Deep
convection related to Wanda has diminished since overnight but
the low level circulation remains well defined. 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.

Locally Heavy Rainfall expected across portions of Central America:
A low pressure system located along the eastern coast of Costa
Rica is producing some disorganized showers and thunderstorms over
the southwestern Caribbean Sea. This system is expected to move
westward over Central America later today, and significant
development is unlikely due to its interaction with land. However,
this disturbance will still produce locally heavy rainfall across
portions of southern Nicaragua, Costa Rica, and Panama through
today, which could result in flooding and mudslides. By Wednesday,
the system is forecast to move into the far eastern portion of the
eastern Pacific basin. In addition, a shearline in the Gulf of
Honduras is forecast to support rainfall in parts of Honduras,
Guatemala and Belize through early Fri. A moist and unstable
atmosphere is already in place over most of Central America along
with moist southwest winds south of the monsoon trough. All these
ingredients are supporting scattered showers and thunderstorms
over northern Honduras, including the Bay Islands, eastern
Nicaragua and some areas of Costa Rica and Panama. Refer to the
latest NHC Tropical Weather Outlook at www.hurricanes.gov for more
details, and consult products from your local meteorological
offices.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic Ocean through The Gambia/Senegal
border near 13N17W to 07N22W. The ITCZ then continues from 07N22W to
06N30W to 07N37W to the coast of French Guiana. Isolated to scattered
moderate convection is observed from 01N to 05N between 10W and 30W.

GULF OF MEXICO...

A 1033 mb high pressure system over the central United States
extends a ridge southward into the Gulf of Mexico. The dry
continental airmass that moved into the region behind the previous
cold front continues to limit the development of showers and
thunderstorms. Cold air stratocumulus clouds are noted over the
NE Gulf with patches of low level moisture and possible light
showers elsewhere. One of then is over the SE Gulf affecting the
province of Pinar del Rio in Cuba. The weak pressure gradient is
resulting in moderate or weaker anticyclonic winds and 1-3 ft
seas. At 12Z, a cold front is analyzed from north Florida to SE
Louisiana. A reinforcing cold airmass follows the front. As a
result, unseasonably cool temperatures are expected to persist
over the central and eastern US.

For the forecast, gentle to moderate N to NE winds across the
basin will increase to moderate to fresh over the northern half of
the Gulf by Thu morning ahead of a front expected to extend along
the northern Gulf coastal waters by Wed night. Fresh to strong N
to NE winds are forecast for the waters W of 94W early Thu evening
through Fri, decreasing to moderate to fresh in the region of
Veracruz on Sat. 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, allowing
seas to gradually subside through late Sat.

CARIBBEAN SEA...

Locally Heavy Rainfall is expected across portions of Central
America. Please, see the Special Features section for details. A
shearline extends from near Cabo Cruz in eastern Cuba to near the
Bay Islands in the Gulf of Honduras. Moderate to fresh N to NE
winds are west of this line, which is also supporting scattered
showers and tstms between the Cayman Islands and the Gulf of
Honduras. This feature will slowly shift westward through Wed,
supporting the continuation of showers and fresh NE winds in the
NW Caribbean. An upper-level low spinning between Puerto Rico and
Hispaniola supports some shower activity over the NE Caribbean,
especially across the Anegada Passage, US/UK Virgin Islands and
the northern Leeward Islands. Unsettled conditions will continue
over Puerto Rico, the Virgin Islands and Hispaniola over the next
couple of days under the influence of the upper level trough.
Recent scatterometer data indicate fresh to locally strong trades
near the coast of Colombia with mainly gentle to moderate winds
elsewhere. Seas are 4-6 ft over the south-central and SW
Caribbean, 4-5 ft W of the shearline, and 2-4 ft elsewhere.

For the forecast, moderate to fresh NE to E winds over the SW
Caribbean will diminish this evening as a low pressure off the
coast of SE Costa Rica weakens into a surface trough through Wed.
A weak pressure gradient will support mainly gentle to moderate
trade winds across the central and E basin through Sat night.
Otherwise, moderate to fresh N winds are forecast for the NW
Caribbean waters Fri evening through Sat night in the wake of a
cold front.

ATLANTIC OCEAN...

A cold front enters the forecast area near 31N52W, then continues
SW to near 26N61W where it becomes stationary to eastern Cuba.
Moderate to locally fresh northerly winds and seas in the 6-7 ft
range are in the wake of the cold front. Patches of low level
clouds with possible showers are noted along the frontal boundary.
E of the front, a surface trough extends from 31N37W to 22N44W to
19N57W. Seas are 8-10 ft in northerly swell N of 25N between the
front and the trough. Farther east, a 1012 mb low pressure is
seen near 21N35W with a trough along it. This is the reflexion of
an upper level trough. A band of moderate to isolated strong
convection is just E of the surface trough and covers the waters
from 18N to 29N between 30W and 35W. Fresh to strong southerly
winds are noted in association with this convective activity.
Between the trough and the W coast of Africa mainly moderate
trades prevail with gentle to moderate winds elsewhere across the
Atlantic. The eastern Atlantic is under the influence of a 1024 mb
high pressure located mid-way between the Azores and the Madeira
Islands.

The Cumbre Vieja volcano, on the island of La Palma in the Canary
Islands, has been erupting since 19 September 2021. Ash cloud
detectable on satellite imagery extending eastward 20 nm. Low
volcanic ash concentration elsewhere. 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/.

For the forecast west of 65W, the stationary front extending to
eastern Cuba, will continue to weaken today. 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 NE Florida
Thu night. A low will develop along the front by Fri evening and
gale force winds are anticipated to develop over the NW offshore
waters through Sat. The cold front is expected to extend from
31N74W to central Cuba by Sat night.

$$
GR
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