[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 172107
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sun Jan 17 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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

Caribbean Gale Warning: High pressure building north of the area
will support strong to near gale force winds over the south-
central Caribbean through the middle of the week. Overnight land
breezes will allow these winds to pulse to gale force within 90 nm
off the coast of Colombia, mainly between Cartagena and
Barranquilla. Please read the latest NWS High Seas Forecast
issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near the
border of Sierra Leone and Liberia at 07N11W to 06N14W. The ITCZ
continues from 06N14W to 04N26W to the coast of Brazil near
02N50W. Scattered moderate and isolated strong convection is noted
from 02N-08N between 18W-48W.

GULF OF MEXICO...

A surface ridge extends from 1021 mb high pressure centered near
the central Texas coast at 29N96W through the Straits of Florida.
Fairly dry conditions are present, however broken to overcast
clouds persist across the southeast half of the Gulf. No
significant showers or thunderstorms are noted. Earlier
scatterometer data indicated mainly gentle to moderate
anticyclonic winds across the basin. Buoy, ship and altimeter data
indicated seas of 3 ft or less across the northwest half of the
basin, and 3-5 ft across the southeast half of the basin in
lingering and decaying northwest-north swell generated by a cold
front passage a couple of days ago.

High pressure will dominate the Gulf waters over the next several
days. Fresh to strong southerly return flow will set up over the
northwest Gulf Mon night into Tue between the high pressure and
lower pressure farther west over northeast Mexico. These winds
will diminish some by the middle of the week. Fresh to locally
strong winds are expected near and to the northwest of the
Yucatan Peninsula through Wed night due to local effects.

CARIBBEAN SEA...

There is a gale warning in effect for the south-central Caribbean.
Please see the Special Features section above for more details.

A stationary front extends across the northwest Caribbean from
central Cuba to north-central Honduras. Upper level ridging and
deep layered dry air is allowing for drier conditions in the
eastern Caribbean. Earlier scatterometer data showed moderate to
fresh N-NE winds west the front and south of 19N, with gentle to
moderate N-NE winds west of the front and N of 19N. Moderate to
locally fresh trades prevail east of the front outside of the
south-central Caribbean as described in the Special Features
section above. Seas are mainly 4-7 ft across the basin, except to
8 ft in the south-central Caribbean.

The stationary front will dissipate through Mon. High pressure
building in the wake of the front north of the region will bring
increasing winds and building seas over the central and northwest
Caribbean. Fresh to strong NE winds are also expected in the lee
of eastern Cuba starting Mon night.

ATLANTIC OCEAN...

A cold front extends from near 32N58W to 24N71W where it then
continues as a stationary front across the southeast Bahamas to
central Cuba. Scattered showers are possible in the vicinity of
the front, with isolated thunderstorms possible south of 26N
within 90-120 nm south-southeast of the front. The main upper
level dynamics supporting the front are lifting out to the north,
allowing sustained winds and gusts to continue to diminish over
the waters, except north of 29N within 60-90 nm ahead of the
front where earlier scatterometer data indicated fresh to strong
SW winds. Gentle to moderate winds prevail elsewhere west of 55W.
Even though winds associated with the front have mainly
diminished, lingering and large NW swell of 7-11 ft persists north
of 26N and west of the front to around 75W, and north of 29N and
east of the front to 60W. Seas of 3-6 ft cover the remainder of
the waters outside of the Bahamas, with seas mainly 3 ft or less
inside the Bahamas.

For the forecast west of 55W, the front will completely stall
tonight while a reinforcing by cold front moves into the area
tonight into Mon. The merging front will extend from 27N65W to
eastern Cuba Mon night, then reach from 24N65W to eastern Cuba on
Tue while gradually weakening through the middle of the week.
Another cold front will move southward into the waters between
Bermuda and northeast Florida Wed night, and dissipate along 27N
by late Thu. Another cold front is forecast to reach the northern
waters on Fri.

Farther east, a cold front extends from the Azores to near
30N38W, denting a ridge that prevails across the waters north of
20N. The ridge is supporting a broad area of moderate to fresh
trade winds, with locally strong winds and accompanying 6-9 ft
seas south of 22N, with gentle to moderate anticyclonic winds
north of 22N. Seas are mainly 4-7 ft from 22N to 26N, with 7-15 ft
seas north of 26N, the highest along 32N, in large NW swell
generated by the parent low of the cold front located well north
of the area.

$$
Lewitsky
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