[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270937
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Dec 27 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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...SPECIAL FEATURES...

...Atlantic Gale Warning...
A deepening storm center located southeast of Nova Scotia
continues to move eastward into the central Atlantic. An
associated cold front is moving southward between Bermuda and
northeast Florida will continue to move southeast and reach a
position from 31N45W to 24N60W to 27N83W by late tonight, and
from 31N35W to near the Leeward Islands the Turks and Caicos by
late Tue. Gale force winds following the front will reach as far
south as 29N between 35W and 45W from late this morning through
tonight. In addition, large swell in excess of 8 ft will reach as
far south as 22N through mid week, with seas as high as 20 ft
along 31N today and tonight. Both winds and seas should begin to
subside Tue morning as the low pressure lifts out to the
northeast. 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
information.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Guinea near 10N14W
to 10N20W. The ITCZ extends continues from 05N20W through 03N40W.
No significant convection is noted.

...GULF OF MEXICO...

1020 mb high pressure is centered over the eastern Gulf of Mexico
off Tampa Bay. Buoy data and a scatterometer satellite pass from
03 UTC indicated fresh SE winds over the northwest Gulf, with 3 to
5 ft seas. Gentle to moderate winds and 1 to 3 ft seas are evident
elsewhere. No major showers or thunderstorms are noted across the
basin.

For the forecast, the high pressure over the eastern Gulf will
continue to support moderate to fresh winds across the central
and western Gulf through mid week. The high pressure will shift
eastward, allowing gentle to moderate winds and slight to moderate
seas across the entire basin Thu, as a weak frontal boundary
stalls and dissipates along the Texas coast. Looking ahead, SE to
S winds may increase over the western Gulf by late Fri as low
pressure moves into the central and southern plains.

...CARIBBEAN SEA...

A recent scatterometer pass confirmed fresh to strong northeast
winds off the coast of Colombia. A concurrent altimeter pass
showed seas to 8 ft there as well. A trough extends from the
southeast Yucatan Peninsula to eastern Honduras. A pair of ship
observations showed fresh SE winds over the northwest Caribbean,
south of the Yucatan Channel, between the trough and the high
pressure farther north. Elsewhere, 1020 mb high pressure north of
the area over the eastern Gulf of Mexico dominates the pattern
over the Caribbean Sea generating a moderate to fresh trades
mostly across the eastern and central basin, to include the
Windward Passage and in the lee of central Cuba. In addition to
the 6 to 8 ft off central Colombia, seas are roughly 4 to 6 ft
across the basin except for 2 to 4 ft in the northwest Caribbean.
Regional radar shows a few showers over the Leeward Islands
embedded in the trade wind flow, but no significant shower or
thunderstorms activity is evident elsewhere.

For the forecast, the high pressure over the eastern Gulf of
Mexico will continue to maintain moderate to fresh winds across
the Caribbean into Tue, with strong winds pulsing off Colombia
mainly at night. The high pressure will move eastward into the
western Atlantic and strengthen mid to late week, support fresh to
strong winds over parts of the central Caribbean and Gulf of
Honduras by mid week.

...ATLANTIC OCEAN...

Please read the Special Features section on a Gale Warning issued
for the central Atlantic.

A trough is analyzed ahead of the aforementioned cold front
approaching from the northwest. Scattered showers and
thunderstorms are active within 90 nm east of the trough. The cold
front reaches as far south as 29N between 55W and 75W, displacing
the subtropical ridge southward to a position from north of the
Canary Islands across the Atlantic to the southern Bahamas to
high pressure over the eastern Gulf. Fresh to near gale force
winds are active ahead of the front north of 26N between 35W and
65W, along with seas of 8 to 12 ft. Elsewhere, gentle to moderate
winds and 5 to 7 ft seas are noted along the ridge axis, moderate
to fresh trade winds and seas to 8 ft south of 12N.

For the forecast, the cold front will move southeast of the
region through Wed. High pressure currently over the eastern Gulf
will shift eastward following the front, and strengthen northeast
of the Bahamas Tue through Fri.

High pressure near central Florida dominates the western
Atlantic. Winds are generally increasing with latitude from a
gentle to moderate northeasterly breeze and 3-5 ft seas near the
Greater Antilles to a fresh westerly breeze with 8-10 ft seas
north of 29N. Seas range 8-10 ft N of 28N and E of 70W, otherwise
seas range 3 to 6 ft across the western Atlantic. East of 65W, a
strong westerly breeze and greater fetch area are causing higher
seas to propagate farther south with altimeter data confirming
seas are greater than 10 ft north of 30N while 8 ft seas reach as
far south as 25N in the central Atlantic.

In the eastern Atlantic, a dying cold front extends from 31N28W
to 28N35W where a dying stationary boundary continues to 26N46W. A
fresh breeze is noted along the front. Moderate trade winds are
noted south of 20N. Gentle winds dominate the remainder of the
basin from 20N to 27N with moderate northerly swell.

For the forecast, high pressure over the Bahamas will shift
slightly west over Florida ahead of a cold front moving into the
waters between northeast Florida and Bermuda tonight. The front
will continue to move southeast of the region through Wed. The
high pressure will shift eastward following the front, and
strengthen northeast of the Bahamas Tue through Fri.

$$
Christensen
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