[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 170548
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Sun Dec 17 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
0540 UTC.

..SPECIAL FEATURES...

Gale Warning for Gulf of Mexico, Florida Offshore and Western
Atlantic: A stationary front extends westward from 23N61W to
25N77W, then continues as a warm front to a deepening 1004 mb low
at the central Gulf of Mexico near 26N85W. To the north, there
are two strong high pressures, a 1030 mb near 35N66W and the
1030 mb Bermuda High. Tight gradient between these features will
maintain near-gale to gale ENE to E winds along with 10 to 14 ft
seas across the central and eastern-central Gulf of Mexico,
southeast Florida offshore waters tonight. As the low at the
central Gulf of Mexico tracks northeastward toward the Florida
Big Bend area and deepens further, these winds and seas will
shift into the northeastern Gulf of Mexico, and the offshore
waters of central/northeast Florida and northwest Bahamas. This
low is expected to cross northern Florida and southern Georgia
early Sunday morning and exit into the western Atlantic on by
Sunday afternoon. This will cause gale southerly winds and very
rough seas of 16 to 23 ft to shift northward and eastward into
the western Atlantic waters N of 26N and W of 73W. On the other
hand, this will allow winds and seas across the eastern Gulf of
Mexico and southeast Florida offshore waters to gradually
subside.

Residual Large ENE Swell Event E of the Bahamas:
Decaying ENE swell will remain large enough to sustain 12 to 13
ft seas from 22N to 26N between 70.5W and the Bahamas through
tonight. Afterward, the ENE swell will subside further and allow
seas to drop below 12 ft Sun morning. By Sunday afternoon, seas
will rise again as winds increase to between near-gale and gale-
force in respond to a deepening low pressure moving across
norther Florida and southern Georgia.

Gale Warning at the Central Atlantic:
Tight pressure gradient in the area continues to support
gale-force winds. Latest satellite scatterometer data show
near-gale to gale-force NE winds north of 29N between 46.5W and
50W. Seas of 12 to 13 ft are in this area. As the pressure
gradient gradually weakens, winds are expected to fall below
gale-force by Sun afternoon. However, a broad area of 12 to 19
ft seas reinforce by increasing large NE swell will sink
southward and dominate the waters north of 25N between 49W and
58W.

Please read the latest NWS High Seas and Offshore Waters
Forecasts issued by the National Hurricane Center at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and
https://www.nhc.noaa.gov/marine/offshores.php for more details of
these events.

...MONSOON TROUGH/ITCZ...

The monsoon trough exits the Africa continent near 09N13.5W to
06N17W. The ITCZ extends westward from 06N17W to 04N46W.
Scattered moderate convection from 01N to 17N between the west
coast of Africa and 27W. Another area of similar convection is
noted from 02N to 07N between 34W and 47W.

...GULF OF MEXICO...

Please read the Special Features section above for details on the
Gale Warning in effect for the E Gulf waters.

Besides the deepening low and stationary front mentioned above, a
surface trough runs northward from the Yucatan Channel through
the low to the central Louisiana coast. Clusters of moderate to
strong convection prevail across the eastern half of the basin.
To the NW, a cold front is analyzed from 29N92W to 19N96W.

Outside the Gale Warning area, fresh to strong SE to S winds and
seas of 8 to 10 ft dominate the southeastern Gulf, including the
Florida Straits. Fresh to strong NW to N  winds and 8 to 14 ft
seas are present across the western Gulf, including the western
Bay of Campeche.

For the forecast, a 1004 mb low pressure currently near 27N85.5W
will continue to strengthen as it moves NE tonight and into
Florida near the Big Bend overnight. This will produce
additional gales in the NE Gulf tonight, to the N and then to
the NW of the low. Thunderstorms in association with this low
will provide locally higher winds and seas into Sun morning over
the eastern Gulf of Mexico. A cold front will trail from the
low, moving SE of the Gulf and into the NW Caribbean Sun
morning. Strong north winds will continue behind this front in
the northern and western Gulf into Sun. High pressure will then
settle in over the area through early next week allowing for
marine conditions to gradually improve.

...CARIBBEAN SEA...

A surface trough runs southeastward from the Yucatan Channel to
the Gulf of Honduras. Convergent southeasterly winds east of the
trough axis are triggering scattered showers and thunderstorms
near western Cuba and the Cayman Islands. Otherwise, a 1030 mb
Bermuda. Gentle to moderate easterly winds and 4 to 6 ft seas
prevail in the central and eastern Caribbean. Light to gentle S
to W winds and 4 to 6 ft seas in moderate easterly swell are
evident at the Gulf of Honduras and southwestern basin.

For the forecast, strong high pressure N of the region across
the western Atlantic along 34N will support fresh trade winds
across the north-central basin tonight, before the high pressure
shifts E and weakens, causing winds to gradually diminish Sun. A
cold front will move through the Yucatan Channel and into the NW
Caribbean tonight, stretch from eastern Cuba to Costa Rica Mon
morning, then stall and weaken from central Hispaniola to Panama
by Wed. Fresh to strong NW to N winds will follow this front,
becoming N to NE on Wed.

...ATLANTIC OCEAN...

Please read the Special Features section about a ongoing Gale
Warning and significant swell event.

A stationary front extends westward from a 1016 mb low near
31N36W, then curves southwestward as a cold front before
transition to a stationary front at 23N61W to across the central
Bahamas to beyond the Great Bahama Bank. Scattered showers are
noted W of 73W. To the E, a surface trough extends from the low
near 31N36W to 22N44W with scattered showers. Similar convection
is noted north of 28N between 41W and 44W.

Outside the Gale Warning and significant swell areas, fresh to
strong NE to E winds and seas of 8 to 12 ft are evident N of 18N
between 60W and the Florida east coast. Near the Canary and Cabo
Verde Islands, moderate to fresh NE to ENE trades and 4 to 7 ft
seas in moderate northerly swell are noted north of 06N between
the Africa coast and 30W. For the central Atlantic, light to
gentle winds and seas at 5 to 7 ft in moderate mixed swell are
found from 17N to 27.5N between 35W and 50W. For the tropical
Atlantic, gentle to moderate NE winds and 5 to 7 ft seas
dominate from 05N to 20N between 30W and the Lesser Antilles.
Light to gentle southerly winds and 5 to 7 ft in mixed swell
prevail for the remainder of the Atlantic Basin.

For the forecast, a stationary front extends from 23N55W to
22N59W then W-NW through the NW Bahamas and across S Florida.
This front will weaken tonight and dissipate on Sun. Strong to
gale-force E-SE winds are noted N of this boundary from 25N to
30N W of 76W early tonight, including the NW Bahamas and
offshore Florida. Deepening low pressure in the E Gulf of Mexico
will move NE and into Florida tonight, then move across the far
NW Atlantic waters Sun and move N of the area Sun night. SE
gales will develop offshore Florida later tonight and Sun, ahead
of the low, then spread E and NE with time, ahead of a cold
front that will trail this low. Behind the front, NW gales will
also develop N of 28N by Sun night. Ahead of the low and the
cold front tonight through Sun night, strong thunderstorms will
likely produce locally higher winds and seas. The cold front
will reach 30N75W to Central Cuba by Sun evening, then extend
from 31N68W to Haiti by Mon night. The front will then stall
into the middle of next week.

$$
KRV
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