NWS National Hurricane Center Miami FL
1215 UTC Sat Dec 21 2024
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
1030 UTC.
..MONSOON TROUGH/ITCZ...
The monsoon trough enters the Atlantic near 01N09E and extends to
02N01W. The ITCZ continues from 02N01W to 03N51W. Widely
scattered moderate convection is observed from 03N to 07N between
24W and 41W.
...GULF OF MEXICO...
A weak cold front extends across the Florida Straits through the
Yucatan Channel into the northern Yucatan Peninsula. A few
showers are seen in the western Gulf west of 92W. A strong ridge
over the northern US extends into the Gulf of Mexico, forcing
fresh to locally strong N winds in the northern Gulf waters,
especially north of 28N. Seas in these waters are 4-6 ft.
Elsewhere, moderate to locally fresh N winds and moderate seas are
prevalent.
For the forecast, fresh to locally strong N to NE winds will
occur this morning in the wake of a dissipated cold front north of
28N. Otherwise, moderate to locally fresh N to NE winds will
prevail over the remainder of the Gulf today in the wake of a cold
front moving into the northwestern Caribbean. High pressure will
build over the central United States this weekend and drift slowly
eastward, and ridging will extend into the Gulf of Mexico,
resulting into moderate NE to E winds this weekend into next week.
...CARIBBEAN SEA...
A weakening front extends from central Cuba to NE Yucatan, but no
significant convection is noted with this boundary. Farther east,
a surface trough and divergence aloft support scattered moderate
to locally strong convection in the north-central Caribbean,
affecting portions of Hispaniola, Puerto Rico and the US Virgin
Islands. Localized heavy rainfall may occur, resulting in flash
flooding. Scattered moderate to strong convection is also noted in
the SW Caribbean waters, impacting SE Nicaragua, Costa Rica and
Panama. Elsewhere, generally dry conditions are present. Moderate
to locally fresh NE-E winds and moderate seas are noted through
the basin. However, due to the presence of the surface trough,
weaker winds are noted in the north-central Caribbean waters.
For the forecast, moderate to locally fresh NE winds will occur
across the western half of the Caribbean through Sun as a series
of weakening cold fronts drift southward and dissipate this
weekend. Elsewhere, moderate to locally fresh trades will prevail
over the central and eastern Caribbean. Slight to moderate seas
will dominate the basin this weekend. Looking ahead, high pressure
will build over the eastern United States and western Atlantic
early next week in the wake of multiple cold fronts moving off the
east coast. A strengthening pressure gradient between these
features will lead to fresh to locally strong NE to E winds across
much of the Caribbean Sun night through Wed, particularly through
the Windward Passage.
...ATLANTIC OCEAN...
A cold front extends from a low pressure system off New England to
the NW Bahamas and the Florida Straits. Another frontal boundary
is analyzed ahead, extending from near 31N69W to the central
Bahamas. A surface trough extends from 30N67W to a 1013 mb low
pressure just north of the Turks and Caicos Islands and continuing
to Haiti. Divergence aloft is sustaining scattered showers and
isolated thunderstorms east of the surface tough to 57W. Fresh to
strong W-NW winds and seas of 6-9 ft are occurring behind the
frontal boundaries and north of the Bahamas. Meanwhile, fresh to
locally strong SE-S winds are noted between 55W and 63W. Seas in
the area described are also 6-9 ft. Elsewhere in the SW North
Atlantic (west of 55W), moderate or weaker winds and moderate seas
are prevalent.
Farther east, a 1010 mb low pressure system centered near 32N43W
extends a stationary front southward from a triple point axis near
31N45W to 17N50W. Scattered moderate to isolated strong
convection is found ahead of the frontal boundary to 30W and north
of 22N. The pressure gradient between a 1041 mb ridge just north
of the Azores and the aforementioned low, front and lower
pressures in the deep tropics result in fresh to strong NE-E
winds east of the front and north of 18N. Seas in these waters are
moderate to rough, peaking near 10 ft off Morocco and 31N37W.
Mariners are advised that gale-force winds are likely occurring in
association with the strongest convection. Moderate or weaker
winds and moderate seas are prevalent elsewhere.
For the forecast W of 55W, a series of cold fronts moving off the
southeastern coast of the United States will progress slowly
eastward this weekend into early next week. Fresh to strong NW
winds will occur behind these fronts north of 27.5N this morning,
with the strongest winds occurring north of 29.5N and west of 72W.
Rough seas associated with these fronts will spread south and
east, with seas in excess of 8 ft occurring north of 27N. Farther
east, ridging will drift eastward, and fresh S to SE winds will
occur through this morning along the periphery of the ridge,
generally north of 20N and east of 65W. South of 20N, moderate to
at times fresh trades will prevail into the middle of next week.
Looking ahead, widespread fresh to locally strong NE winds and
rough seas will redevelop north of 20N by early next week as
strong high pressure builds across the western Atlantic and into
the local region, behind a weakening cold front.
$$
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