[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270521
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1221 AM EST Tue Feb 27 2018

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
0300 UTC.

...SPECIAL FEATURES...

A strong 966 mb low pressure system with hurricane force winds
centered over the north-central Atlantic near 39.5N33W supports a
cold front from 37N24W to 24N40W to 27N55W. A strong pressure
gradient associated with the deep low pressure and cold air
advection associated with cold front are supporting gale force
winds north of the front and east to 35W. Gale conditions are
forecast to prevail through tonight then will gradually diminish
as the low pressure moves farther away from the area and the front
dissipates. Gale force winds are also occurring ahead of the front
as noted in a recent scatterometer pass, impacting the area east
of 35W to the Canary Islands. Altimeter satellite passes are
showing seas of 15 to 25 ft in northerly swell north of 20N and
east of 50W. For more details, refer to the NHC High Seas
Forecast under AWIPS/WMO Headers MIAHSFAT2/FZNT02 KNHC.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the eastern Atlantic through the coast
of Liberia near 06.5N10.5W to 01N16W, where it transitions to the
intertropical convergence zone and continues to the coast of
Brazil near 03N44W. Scattered moderate convection is from 02N to
04N between 20W and 25W, and from 02S to 00N between 25W and 28W.

...DISCUSSION...

GULF OF MEXICO...

A weakening stationary front reaches from near Panama City
Florida to Brownsville Texas. Radar from the across the northern
Gulf shows a few showers along and north of the frontal boundary,
mainly over the northeast Gulf, and what may be light rain or
drizzle in patches over the north central and northwest Gulf.
Dewpoints are in the upper 60s to lower 70s over the northwest
Gulf, where platforms are showing areas of fog. Light southeast
winds are noted south of the front with 2 to 4 ft seas.

For the forecast, the front will weaken through tonight. High
pressure will build across the region Tue. Another, stronger cold
front will move into the NW Gulf Wed night. Gale conditions are
possible over the SW Gulf Thu night behind this front.

CARIBBEAN SEA...

High pressure north of the area centered between Bermuda and the
northern Bahamas is supporting fresh to strong trade winds across
the south central Caribbean and in the lee of Cuba. Moderate to
fresh trade winds persist elsewhere. An upper low is centered
north of the Mona Passage near 21.5N 68.5W with a sharp upper
trough reaching to Nicaragua. This is supporting a few showers
over Hispaniola and over portions of the northeast Caribbean. land
based observations near Santa Marta Colombia show strong trade
winds currently, and this is indicative of the strong flow off
Colombia expected to reach near gale force overnight due to added
drainage effects.

Little change is expected over the next several days with strong
winds pulsing off Colombia, and possibly the Windward Passage
through mid week. Large long period swells will reach the Atlantic
passages in the Leeward and Windward Islands late in the week.

ATLANTIC OCEAN...

A weak pressure pattern dominates the Atlantic waters west of 50W,
focuses on 1023 mb high pressure centered 28N68W, supporting
gentle to light winds north of 22N and moderate trade winds south
of 22N. Scattered showers and thunderstorms are active from 22N
to 24N between 65W and 70W associated with an upper low near
22N66W.

Looking ahead, a cold front will move off the southeast coast of
the U.S. Tue, and reach the central Bahamas Wed evening, as high
pressure builds north of the front. Strong low pres north of the
area will bring a cold front to area Thu night, with deteriorating
conditions over the waters north of 27N. The system will support
gales Fri night through Sat night over the northeast waters. A
significant swell event will accompany this system, affecting all
waters east of north Florida and Bahamas at the end of the week.

East of 50W, fresh to strong northwest 25N to 30N outside the
areas of strong to gale force winds noted in the Special Features
sections. Because the subtropical ridge is disrupted by the deep
low pressure over the north central Atlantic, only gentle to
moderate trade winds deeper into the tropics. Northerly swell of 8
to 8 to 12 ft is reaching as far south as 15N. Looking ahead for
the waters east of 50W, winds and seas will gradually subside
north of 25N through mid week, just ahead of another powerful low
pressure system approaching from the western Atlantic, brining
strong to near gale force winds and large seas to the area north
of 20N between 40W and 50W by late week.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Christensen
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