[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 220605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Dec 22 2020

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 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...MONSOON TROUGH/ITCZ...
The monsoon trough axis extends from the coast of Sierra Leone
near 08N13W to 07N15W, where latest scatterometer shows that it
transitions to the ITCZ to 05N25W to 05N35W and to the coast of
Brazil near 03N51W. Scattered moderate to isolated strong
convection is within 180 nm either side of the ITCZ between
26W-32W and within 60 nm north of the ITCZ between 15W-18W and
between 20W-24W. Scattered moderate convection is within 120 nm
south of the ITCZ between 18W-23W, within 120 nm north of the
ITCZ between 32W-36W and between 44W-48W and within 60 nm south
of the ITCZ between 33W-39W.

GULF OF MEXICO...

Now that the cold front has pushed farther away from the Gulf and
into the northwestern Caribbean Sea, high pressure has settled in
over the area as a 1024 mb high is centered over the far north-
central Gulf at 29N91W. Patches of broken to overcast low-level
clouds and stratus are confined to the SW Gulf and far western
gulf from 22N to 25N west of 96W. Gentle to moderate winds are
over most of the basin, except for light to gentle east to
southeast winds over the NW Gulf waters and light to gentle west
to northwest winds over the NE Gulf waters. The high pressure will
move northeastward toward the Carolinas. This will allow for
generally fresh southerly return flow to dominate most of the Gulf
waters on Wed.

The next cold front is forecast to enter the NW Gulf by Wed
evening followed by strong to gale-force winds and building seas.
Strong gale-force winds are expected first near Tampico by early
Thu morning, then near the Veracruz area early Thu afternoon.
Currently, marine guidance suggests N winds of 35-40 kt and
building seas of 12 or 13 ft. The front is forecast to exit the
Gulf by late Thu.

CARIBBEAN SEA...

As of 22/0300 UTC, the cold front that in previous days moved
across the Gulf of Mexico extends from western Cuba to just south
of Cozumel and dissipating from there to inland the Yucatan
Peninsula at 19N89W. Scattered to broken low clouds, with possible
isolated showers are along and within 60 nm north of the front.
Another and stronger cold front is expected to reach the Yucatan
Channel and western Cuba by Thu night. Fresh to strong northerly
winds will follow the front as it is forecast to reach from
central Cuba to the Gulf of Honduras by Fri morning.

Patches of low level moisture, embedded in the trade wind flow,
are noted moving westward across the basin. Isolated to scattered
passing showers are possible with some of these clouds.

Recent ASCAT data revealed the presence of fresh to strong trade
winds over the south-central Caribbean and S of Haiti, while
moderate to fresh winds dominate the remainder of the east and
central Caribbean. Fresh to strong trade winds are expected near
the coast of Colombia through Thu, with seas of 7-10 ft. The trade
wind flow will weaken toward the end of the week as a strong cold
front reaches the NW Caribbean.

ATLANTIC OCEAN...

As of 03Z, a cold front extends from near 32N69W to the central
Bahamas and to west-central Cuba. A pre-frontal trough extends
from near 32N67W to 27N71W. Scattered showers and thunderstorms
are along and with 30-60 nm east of the trough.

Farther east, a cold front enters the discussion area at 32N29W
continues southwestward to near 29N35W, where it becomes
weakening stationary to 26N44W. Pockets of low-level moisture, in
the form of broken to overcast low clouds with isolated showers,
are near and along this frontal boundary. Seas in the range of 8
to 13 ft in northerly swell are noted behind the front, that will
gradually weaken over the forecast waters through this evening.
The pressure gradient between strong high pressure behind the
front front and lower pressures found in the vicinity of the ITCZ
supports moderate to fresh trades north of the ITCZ to about 14N
between 27W-44W based on recent ASCAT data. A ridge prevails over
the far eastern Atlantic.

$$
Aguirre
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