[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 120548
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Sat Dec 12 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
0520 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal border areas of
Guinea and Sierra Leone near 10N13W, to 05N23W. The ITCZ
continues from 05N23W, to 03N26W, 06N38W, and to 04N48W.
Precipitation: scattered to numerous strong in clusters is from
02N to 05N between 27W and 31W, and from 06N to 08N between 21W
and 32W. Isolated moderate to locally strong is elsewhere from
10N southward from 60W eastward.

GULF OF MEXICO...

An upper level ridge extends from Florida to Honduras. Broad
upper level anticyclonic wind flow spans
the Gulf of Mexico.

A surface ridge extends from north central Florida, toward the
Yucatan Peninsula, to 21N95W.

High pressure, extending from the NW Atlantic Ocean across the N
FL Peninsula to the N central Gulf of Mexico, will shift NE
tonight, as the next cold front reaches the NW Gulf of Mexico
coast. This weak front will move into the NW Gulf of Mexico on
Saturday. The front will move northward, to the north of the
area on Sunday. Another cold front will move into the Gulf of
Mexico on Sunday night. By Monday, this front will reach from
the Florida Panhandle to the Bay of Campeche, with strong N
winds spreading southward behind the front. Minimal gale-force
winds are expected in parts of the western and southwestern Gulf
of Mexico on Monday and Monday evening, across the Mexican
waters from Tampico to Veracruz.

CARIBBEAN SEA...

An upper level ridge extends from the border of Colombia and
Panama, northwestward to the Yucatan Peninsula, spanning all of
Central America. Upper level NW wind moves across the open
waters of the Caribbean Sea, from Central America eastward,
gradually becoming more westerly wind flow crossing into the
eastern one-third of the Caribbean Sea.

A shear line passes through the Atlantic Ocean, from 22N60W to
22N67W, to the northern coast of Haiti. Fresh NE winds are
within 300 nm to the north of the shear line between 54W and
65W. Precipitation: widely scattered moderate to isolated strong
is within 120 nm to 180 nm on either side of the shear line.

Rainshowers are possible, in scattered to broken low level
clouds, that are moving through the area.

The monsoon trough is along 07N/10N from 73W in N Colombia,
beyond Panama. Precipitation: isolated moderate to locally
strong is elsewhere from 13N southward from 78W westward to the
coasts of the countries of Central America.

Strong NE winds will pulse nightly through Monday along the
Colombian coast. An old frontal boundary extends from near
23N65W to the Windward Passage tonight, and it will begin to
drift N and weaken by morning. Weak high pressure will dominate
the basin from Sunday through Wednesday, in order to produce
below normal winds and seas. A weakening cold front will stall
across the Yucatan Channel on Thursday
night.

ATLANTIC OCEAN...

A stationary front extends from 31N46W to 24N55W. A shear line
continues from 24N55W to 22N60W, to 22N67W, to the northern
coast of Haiti. Fresh NE winds are within 300 nm to the north of
the shear line between 54W and 65W. Precipitation: widely
scattered moderate to isolated strong is within 120 nm to 180 nm
on either side of the stationary front and shear line.

Broad and weak upper level cyclonic wind flow covers the area
that is from 07N to 20N between 40W and 60W. A surface trough is
along 23N53W 15N55W 7N55W. Precipitation: isolated moderate to
locally strong is within 270 nm to the east of the trough, and
within 180 nm to the west of the trough, from 12N to 20N.

A 1029 mb high pressure center is near 35N61W. Surface
anticyclonic wind flow covers the Atlantic Ocean to the north of
the stationary front/shear line. A 1031 mb high pressure center
is near 32N26W. Surface anticyclonic wind flow covers the
Atlantic Ocean from 18N northward from the stationary
front/shear line eastward.

A stationary front extends from the central Atlantic Ocean to
23N65W to the Windward Passage. Very active weather will
continue along and south of the front overnight, before it
weakens on Saturday and drifts northward. A high pressure ridge
will dominate the waters that are to the north of this front,
bringing fresh to strong NE to E winds across the NE waters,
from tonight through Saturday night. The ridge then will weaken
considerably across the area, from Sunday through Wednesday. A
cold front will move off the FL coast on Monday night. Strong SW
winds will be ahead of the front, mainly N of 28N.

$$
mt/ss
This weather bulletin was brought to you by:
www.nashvilleweather.net