AXNT20 KNHC 311720
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Fri Mar 31 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 1200 UTC surface analysis and satellite imagery through
Caribbean Gale Warning: A tight pressure gradient between a
surface ridge north of the Caribbean Sea and lower pressures
over Colombia will continue to support winds pulsing to gale
force within 90 nm of the coast of Colombia overnight through
Mon night. Seas are expected to peak around 13 ft each night
under the strongest winds.
Atlantic Significant Swell: A strengthening low pressure system
over the north Atlantic will produce gale to storm-force winds
over the next few days north of our area. The system will send
large NW to N swell southward, with seas greater than 12 ft
entering our northern waters early Sat and then expanding
southeastward. Seas of 12 to 16 ft are forecast to cover an area
east of 53W, making it to 35W by Sunday morning and remaining
mainly north of 26N. By Monday, rough seas will expand farther
southeastward, covering a majority of the eastern subtropical
Atlantic. The highest
seas of 14 to 16 ft are forecast to be confined to the north of
29N between 51W and 37W Sat afternoon through Sun morning. The
significant wave heights will diminish below 12 ft Tue.
Please read the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and Offshore Waters
Forecast at www.nhc.noaa.gov/marine/offshore.php for more
The monsoon trough enters the Atlantic through the coast of
Sierra Leone from 08N13W to 06N15W. The ITCZ begins from this
point and extends SW to 01N30W and to 01S45W. Scattered moderate
convection is noted from 04S to 01N and west of 33W.
GULF OF MEXICO...
High pressure dominates the Gulf of Mexico. Moderate fresh SE
winds and seas of 4-6 ft prevail over most of the Gulf, with
moderate to fresh ESE winds over the eastern Gulf. The strongest
winds are noted in the NW and SW Gulf.
For the forecast, high pressure will shift eastward ahead of a
weakening cold front that will move across the NE Gulf over the
weekend. Atlantic high pressure will build in again over the
area early next week. Pulsing fresh to locally strong winds off
the Yucatan Peninsula will change little into early next week.
Please read the Special Features section for details on a Gale
Warning in the south-central Caribbean Sea.
Pockets of isolated, weak showers are seen across the
north-central and SW Caribbean Sea. However, the dry environment
suppresses the formation of deep convection. Fresh trades
prevail across the eastern and central Caribbean, except for
strong to gale force in the south-central Caribbean. Seas are
5-8 ft, except for 8-12 ft in the strong to gale area. From the
Windward Passage toward NE Jamaica, strong NE winds are likely
occurring with seas around 6 ft. Fresh E winds are likely
occurring in the lee of Cuba and in the Gulf of Honduras with
seas to 5 ft. Moderate trades and 3-4 ft seas prevail elsewhere
across the NW Caribbean.
For the forecast, the pressure gradient between high pressure
north of the area and low pressure over Colombia will support
fresh to strong trade winds over the central Caribbean through
early next week. Winds north of Colombia will pulse to gale-
force each night through Mon night. Winds will pulse to strong
across the approach to the Windward Passage through Sat evening.
Strong winds will pulse in the Gulf of Honduras every night
through the forecast period. Moderate to fresh trade winds will
prevail elsewhere across the Caribbean. Seas will build to 8-9
ft in the Tropical North Atlantic this weekend, then slowly
subside through early next week.
Please read the Special Features section for details on a
Significant swell event forecast for the central and eastern
A cold front sweeps across the subtropical Atlantic, extending
from 31N47W to 25N55W to 23N70W, just north of the Turks and
Caicos. Scattered showers and thunderstorms are within 60 nm of
the boundary, with a concentrated area of convection near the
tail end between 65W and 70W. High pressure is building in
behind the front, allowing for fresh NE winds between 55W and
70W. Winds shift to a more easterly direction over the Bahamas
to the Florida Peninsula. Behind the northern portion of the
front and east of 55W and north of 25N, fresh NNW winds are
noted. Seas are generally 6 to 8 ft at this time, with the rough
swell expected to move in this weekend.
A surface trough intercepting a ridge is allowing for another
area of moderate to fresh ENE winds noted farther east, near and
in the lee of the Canary Islands. Winds and seas of 7 to 9 ft
are noted from 22N to 31N and between 25W and 15W.
The remainder of the basin is dominated by an expansive
subtropical ridge that maintains fairly tranquil weather
conditions. In the tropical Atlantic, from 00N to 20N, and west
of 35W, moderate to fresh NE to ENE trades and 6-7 ft seas are
found. Elsewhere, moderate or weaker winds and moderate seas
For the forecast west of 55W, the cold front will move slowly
southeastward today and reach along 22N-23N tonight before it
weakens and dissipates Sat. Strong high pressure building in the
wake of the front is producing fresh to strong NE to E winds
north of the front and east of the NW Bahamas, and will begin to
diminish W of 65W late tonight. Fresh to strong southwest winds
will develop over the waters offshore northeastern Florida
tonight in advance of the next cold front that will move off the
coast of the southeastern U.S. Sat evening.
This cold front will move southeast and become stationary from
near 31N59W to 27N68W and to 26N73W by Mon night, then weaken
through Tue night. The fresh to strong southwest winds ahead of
the front will shift eastward across the waters north of about
29N through Sun before shifting north of the 31N late Sun night.