648 
AXNT20 KNHC 192337
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0015 UTC Mon Oct 20 2025

Tropical Weather Discussion for North America, Central America
Gulf of America, 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 1800 UTC surface analysis and satellite imagery through 
2300 UTC.

...SPECIAL FEATURES...

Atlantic Significant Swell Event: Large and long period NW swell,
generated by a strong cyclone north of the area, continues to 
spread across the western and central Atlantic waters behind a
frontal boundary. A cold front extends from 31N43W to 24N54W, 
then becomes stationary to 22N74W. Seas greater than 12 ft are N
of 27N between 44W-59W, with peak seas to 14 ft. Elsewhere, seas 
greater than 8 ft are north and west of the front to 76W. N to NW 
swell at a period of 12-14 seconds is analyzed across these 
waters. Seas will gradually subside from SW to NE tonight, with 
seas falling below 12 ft over the discussion waters late tonight.

Please read the latest HIGH SEAS FORECAST issued by the National 
Hurricane Center at website - 
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis near 27W, from 
from 12N southward, moving westward around 5-10 kt. Nearby 
convection is discussed in the monsoon trough/ITCZ section below. 

A central Atlantic tropical wave has its axis near 40W, from 10N 
southward, moving westward at 10-15 kt. Nearby convection is 
discussed in the monsoon trough/ITCZ section below.

An Atlantic tropical wave (Invest AL98) has its axis near 59W, 
from 18N southward, moving westward at 15-20 kt. Scattered
moderate isolated strong convection is S of 17N between 57W and
67W. Fresh to strong E winds are from 13N to 18N betwen 60W and 
64W, with 8-11 ft seas. Recent satellite wind data and surface 
observations indicate that showers and thunderstorms have become 
slightly better organized since yesterday. However, surface 
observations indicate the disturbance still lacks a closed 
circulation. The system is moving quickly westward, which will 
likely limit its development over the next day or so. Thereafter, 
environmental conditions are forecast to become more favorable for
development as the wave slows down over the central Caribbean 
Sea, and a tropical depression is likely to form during the middle
to latter portion of this week. Regardless of development, heavy 
rainfall and gusty winds are expected to continue for portions of 
the Windward and Leeward Islands through Monday morning. There is 
a LOW chance of development through the next 48 hours. For more 
information on the development of this system, please see the 
latest TROPICAL WEATHER OUTLOOK issued by the National Hurricane 
Center at www.hurricanes.gov.

A Caribbean tropical wave has its axis near 66W south of 15N, moving
westward at 10-15 kt. Scattered moderate convection is across the
ABC Islands. 
 
...MONSOON TROUGH/ITCZ... 

Based on satellite derived wind data, no segments of the Monsoon
Trough are analyzed over the tropical Atlantic Ocean. The ITCZ,
with brief breaks near the Tropical Waves described above, extends
from 13N17W and continues to 06N55W. Scattered moderate 
convection is within 180 nm N of the ITCZ across the tropics.

GULF OF AMERICA...

A cold front is analyzed from 30N89W to 27N97W. Moderate to fresh
NE winds are behind the cold front. Ahead of the front, a pre- 
frontal trough extends from 29N85W to 27N86W. Scattered moderate 
convection is N of 26N between 82W and 84W ahead of the trough. 
Elsewhere across the basin, moderate or weaker winds and slight to
moderate seas prevail. Scattered moderate convection is noted in 
the Yucatan Channel.

For the forecast, the cold front will progress southeastward over
the Gulf through early this week. Moderate N to NE winds will 
occur north of the front, with locally fresh winds possible north 
of 27N through Mon morning. High pressure will build over the 
basin in the wake of this front, leading to gentle to moderate 
winds and slight seas over the Gulf. 

CARIBBEAN SEA...

Please see the TROPICAL WAVES section above.

Outside of the tropical waves described above, weak ridging
prevails across the basin. Moderate to locally fresh trades, with
3-5 ft seas, are analyzed in the eastern and central Caribbean.
Light to gentle trades and slight seas are analyzed in the 
western Caribbean. Scattered moderate isolated strong convection 
is from the coast of Panama north to 16N between 76W and 81W. 
Scattered moderate convection is also noted in the Yucatan 
Channel. Seas may be locally higher within the Mona Passage and 
other Atlantic Passages between the islands of the Lesser 
Antilles, due to arriving N swell and the approaching tropical 
wave (AL98). 

For the forecast, moderate trade winds and moderate seas will 
occur across much of the Caribbean today, with pulsing fresh to 
strong winds expected in the south-central basin. Rough seas in N 
swell will continue to propagate through the Atlantic passages 
through early this week. Elsewhere, a tropical wave currently 
crossing the Windward Islands is producing fresh to strong winds, 
rough seas and increasingly organized shower and thunderstorm 
activity. The system is moving quickly westward, which could limit
development over the next day or so, but environmental conditions
are forecast to become more favorable as it slows down in the 
central Caribbean Sea by the middle of this week. A tropical 
depression is likely to form by the middle to latter portion of 
this week in the central Caribbean Sea. Regardless of development,
heavy rainfall and gusty winds are expected to continue for 
portions of the Windward and Leeward Islands through Monday 
morning. There is a low chance of tropical formation within the 
next 48 hours, and a high chance within the next 7 days. 

ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section above for information on a
SIGNIFICANT SWELL EVENT. Please, also see the TROPICAL WAVES 
section above for information on the tropical waves moving across
the basin. 

Outside of the western and central Atlantic, which is described 
in the SIGNIFICANT SWELL EVENT SPECIAL FEATURE, and the Invest 
AL98 region described in the TROPICAL WAVES section, NE to E winds
are gentle to moderate across the basin with moderate ft seas. 
Trades increase to near fresh speeds from 05N to 15N between 40W 
and 52W, and this wind surge has built rough seas. 1022 mb 
subtropical high pressure is centered near 30N33W. 

For the forecast W of 55W, widespread rough seas will continue 
east of 75W this evening, and will propagate through the Atlantic 
passages into the Caribbean Sea through early this week. Seas in 
excess of 8 ft are expected to slowly subside from northwest to 
southeast tonight through Mon night. High pressure will build over
the western Atlantic early this week. An increasing pressure 
gradient between this high and a cold front moving through the 
southeastern United States will support moderate to locally fresh 
E to SE winds near the Bahamas and offshore of Florida into early 
Mon. The cold front is slated to push off the coast Mon morning, 
leading to moderate to fresh N to NE winds offshore of northern 
Florida in the wake of the front. Otherwise, moderate to fresh 
trade winds are expected south of 25N through midweek.

$$
ERA