520 
AXNT20 KNHC 271105
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Nov 27 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 
1045 UTC.

...SPECIAL FEATURES...

Significant Swell Event: Long-period NW swell producing seas of 
12 to 15 ft with period of 14 to 18 seconds is propagating 
through the north-central Atlantic subtropical waters in the 
wake of a weakening old frontal boundary that extends from near 
31N34W to 25N46W and to 25N60W. The swell set will gradually 
subside through Thu. Please read the latest high seas forecast 
that was issued by the National Hurricane Center, at the website-
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the Atlantic from the coast of 
Sierra Leone near 08N13W and continues to 07N21W, where it
transitions to the ITCZ to 04N34W to 02N39W and to 02N47W.
Scattered moderate convection is seen within 180 nm south of 
the ITCZ between 20W and 30W, within 60 nm south of the trough
between 15W and 19W, and within north of the ITCZ between 28W and
34W.

...GULF OF MEXICO...

A stationary front extends from the Florida Panhandle near
Apalachicola southwestward to 27N91W and to 25N95W. Otherwise, 
relatively weak high pressure is present over the basin. 
Overnight ASCAT data indicates gentle to moderate NE winds over 
the far southeastern Gulf and Straits of Florida while light to 
gentle winds are elsewhere over the basin. Both buoy 
observations and recent altimeter satellite data passes show 
that seas are 1 to 3 ft over the Gulf, except for slightly 
higher seas of 3 to 4 ft near NW Cuba and the Straits of 
Florida. 

For the forecast, a stationary front extending from near
Apalachicola, Florida to 28N92W will lift back N as a warm front 
today. A cold front is forecast to enter the NW Gulf waters Thu 
morning. Moderate to fresh southerly winds will develop over the 
western Gulf through tonight ahead of this front, which will reach
from Cedar Key, Florida to near Tampico, Mexico early on Fri 
morning, and from the Straits of Florida to near Veracruz, Mexico 
by early Sat morning. The front will exit the basin later on Sat. 
Fresh to strong northerly winds and building seas will follow this
front. Gusty winds with occasional gusts to gale force may occur 
over the west-central and SW Gulf in the wake of the front on Fri.
High pressure in the wake of the front will shift eastward 
through Sun night as a trough develops in the far western Gulf 
near South Texas and NE Mexico. The resulting gradient should 
bring fresh to strong easterly winds and building seas to those 
waters. 

...CARIBBEAN SEA...

A plume of deep, tropical moisture ahead of a mid to upper-level
trough that stretches from the Bahamas to Cuba and to Honduras is
helping to sustain a large complex of numerous moderate to strong
convection that is over the central Caribbean waters from just N
of the coast of Colombia between 73W and 76W, reaching northward
from there to 17N. The northeast part of the complex extends to 
the SW tip of Haiti. This activity is accompanied by frequent 
lightning, heavy rain likely reducing visibility and gusty winds. 
The eastern portion of the E Pacific monsoon trough extends from 
southern Costa Rica northeastward to low pressure of 1008 mb near 
12N79W, and southeastward from there to inland NW Colombia. 
Scattered showers and isolated thunderstorms are near the trough 
and low.

The pressure gradient between the trough/low and higher pressure 
over the western Atlantic is generally supporting moderate to 
fresh NE to E winds across most of the basin. Seas are in the 
range of about 3 to 5 ft, except for slightly higher seas of
4 to 6 ft over the central and west-portions of the sea.

For the forecast, the pressure gradient between comparatively 
lower pressure over the southwestern Caribbean and higher pressure
over the SW N Atlantic will continue to support moderate to fresh
trades over most of the basin through Sat night. Locally strong 
NE winds are likely in the lee of eastern Cuba through tonight. 
The trades are forecast to be at mostly fresh speeds while 
expanding in coverage across the basin on Sun and Sun night. A 
large area of numerous thunderstorms accompanied by frequent 
lightning, heavy rain likely reducing visibility and gusty winds 
is moving ESE over the waters from Haiti to 11N and between 73W 
and 76W. 

...ATLANTIC OCEAN... 

Please refer to the Special Features section for details about 
the ongoing long-period swell affecting a portion of the 
north-central Atlantic waters.

A trough is analyzed from near 28N71W to Haiti. Overnight ASCAT
data has fresh to locally strong E winds about 300 nm E of the 
trough from 22N to 27N and fresh NE winds west of the trough to 
near 78W. Seas with these winds are 5 to 6 ft. To the NE of the 
trough, high pressure of 1018 mb is centered near 29N60W. Farther 
east, the aforementioned weakening old frontal boundary extends 
from near 31N34W to 25N46W and to 25N60W. Fresh to strong W to NW 
winds are in the wake of the frontal boundary north of about 29N, 
with NW swell extending westward from the front to near 59W and N
of 19N. Relatively weak high pressure, anchored by a 1018 mb high
center that is near 25N32W, is allowing for mostly moderate 
trades farther south over the tropical Atlantic, where 5 to 7 ft 
seas persist. Gentle breezes and 4 to 6 ft seas in northwest swell
remain elsewhere, except for higher seas of 7 to 10 ft in long- 
period N swell over the eastern Atlantic north of 25N and east of
25W.

A broad moisture plume is streaming north-northeastward from the 
central Caribbean Sea to across the northern and central waters 
between 55W and 76W, and also N of 27N between 27W and 55W. 
Scattered showers along with small patches of light to moderate 
rain are underneath these clouds. An area of scattered showers and
thunderstorms is noted within 120 nm either side of the trough 
from 20N to 25N.

For the forecast, high pressure remains over the northern waters 
while a surface trough is along 71W and S of 28N to near the 
southeastern Bahamas and to Haiti. Fresh to locally strong NE to E
winds are east of the trough to near 66W, and fresh NE winds are 
west of the trough to near 78W. The trough will move westward, 
reaching the central Bahamas and eastern Cuba by tonight, and the
NW Bahamas and central Cuba late on Thu before weakening. A cold 
front is expected to move over the NW part of the area Thu night 
into Fri. It is forecast to reach from near 31N70W to South 
Florida by Sat morning, and from near 31N60W to 28N65W, and 
continue as a stationary front to western Cuba by Sun morning. The
cold front portion will then become stationary by Sun night. 
Moderate to fresh winds and moderate seas will follow the front. 

$$
Aguirre