[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 110355
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Sat Mar 11 2023

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 0000 UTC surface analysis and satellite imagery through
0350 UTC.

...SPECIAL FEATURES...

Central Atlantic Gale Warning: A stationary front extends from
31N35W to 20N50W. A new low-pressure center has formed well
behind the front near 36N48W. This has reinforced the gradient,
with recent scatterometer data confirming winds have reached
near gale to gale force north of 29N, between 49W and 55W. These
winds will shift east tonight before lifting north of the area
Sat morning. Seas are currently peaking near 18 ft. Seas in
excess of 12 ft are currently observed between 27W and 64W,
reaching as far south as 23N. The swell from this event will
gradually abate through the weekend.

SW Atlantic Gale Warning: A cold front has entered the SE US
coastal waters tonight. This front will move eastward over the
next few days. Gale force winds will develop ahead of the
frontal boundary early Sat through Sun. Confined mainly north of
28N, the gale force winds will move with the front from near 70W
early Sat to near 45W late Sun. Seas will quickly build to 13 ft
Sat ahead of the front and to near 23 ft Sun behind the front.
Seas greater than 12 ft will remain north of 25N. Winds and seas
will abate early next week.

Please read the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details
on the gale and swell events.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coastal
border of Sierra Leone and Libera near 07N11W to 05N14W. The
ITCZ continues from 05N14W to the equator at 50W. Scattered
moderate with isolated strong convection is observed from the
equator to 06N, between 10W and 25W.

GULF OF MEXICO...

A weak frontal boundary extends from the Florida Big Bend to
28N90W to near Houston. Scattered moderate convection is
observed near the front in the far NE Gulf. Otherwise, high
pressure ridging from the Bahamas to the north central Gulf
dominates the pattern. Gentle to moderate winds and slight seas
prevail across the basin.

For the forecast, the cold front will weaken quickly Sat as it
moves southward across Florida and the adjacent Gulf. Another
cold front is forecast to approach the northern Gulf late Sat
night and Sun, inducing moderate southerly flow across the
entire Gulf. This front should enter the northern Gulf Sun
night, then sink gradually southward through Tue night, then is
expected to weaken across the SE Gulf Wed as it exits the basin.
In response, fresh to strong NE winds, and locally near-gale
winds are expected N of the front Mon through Tue night.

CARIBBEAN SEA...

A weak shear line extends across the eastern Caribbean, from
16N61W to 15N70W. Some low clouds are noted north of the
feature, but there is no deep convection. NE winds are fresh in
the Windward Passage, Mona Passage, in the lee of the Dominican
Republic. NE winds are strong offshore Colombia. Otherwise winds
are gentle to moderate across the basin. Swell to 8 ft is
propagating through the Mona and Anegada Passages. Seas are 4-6
ft offshore Colombia. Otherwise, seas are in the 3-5 ft range
across the basin.

For the forecast, the shearline should dissipate tonight, as
weak high pressure resides just E of the central Bahamas. Large
northerly swell impacting the regional Atlantic waters,
including Caribbean Passages of the NE Caribbean, will gradually
subside Sat through Mon. Trade winds off the coast of Colombia
will pulse to between strong and near-gale force at night
through Sun night. Fresh to strong ESE winds are expected across
the Gulf of Honduras late Sat night through Tue morning. Looking
ahead, a cold front is forecast to enter the northwestern basin
Wed, which will bring fresh to strong NE winds and rising seas.

ATLANTIC OCEAN...

Please read the Special Features section for details on two
separate gale force wind warnings and associated high seas
across the Atlantic forecast waters this week.

A stationary front extends from 31N35W to 20N50W. Scattered
moderate convection is observed ahead of the frontal boundary,
north of 25N and west of 31W. S-SW winds are fresh to strong in
this area. A large area of fresh and stronger winds are also
noted behind the front from 40W to 60W, north of 24N. A
combination of wind driven waves and a northerly swell are
causing rough seas in excess of 8 ft to cover the majority of
the subtropical Atlantic east of the Bahamas and north of 15N.
The only exception is in the eastern Atlantic east of a line
from 31N20W to 15N40W, where seas are in the 6-8 ft range.

For the forecast W of 55W, the stationary boundary should
dissipate through Sat evening. A reinforcing cold front is just
N of the area from 32N52W southwestward to 31N57W and will sweep
eastward across the NE waters tonight through Sat. This feature
will keep strong to gale-force winds to the north of 24N and
east of 60W overnight. Meanwhile, another cold front is exiting
the southeast U.S. coast, and will reach from 31N70W to southern
Florida early Sat morning, generating strong to near-gale
westerly winds and higher seas from the northwest Bahamas
northward. As it moves farther eastward across the western
Atlantic waters, it will produce near-gale to gale winds north
of 27N and east of 72W through Sun. Successive large northerly
swell behind these fronts will persist across the western
Atlantic through the middle of next week.

$$
Flynn
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