016
AXNT20 KNHC 211102
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1215 UTC Thu Aug 21 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 0600 UTC surface analysis and satellite imagery through
1045 UTC.

...SPECIAL FEATURES...

Eastern Tropical Atlantic (AL99):
Showers and thunderstorms associated with a tropical wave located
several hundred miles west-southwest of the Cabo Verde Islands are
starting to show some signs of organization. The shower and
thunderstorm is of the numerous moderate to strong type evident
from 07N to 12N between 32W-40W. Recent satellite-derived wind
data depict that the system does not have a well-defined center.
Environmental conditions appear marginally favorable for
additional development over the next day or so while the system
moves west-southwestward at around 15 mph, and a short- lived
tropical depression could form. By the end of the week,
environmental conditions are expected to become unfavorable for
further development. This system has a medium chance of formation
for the next 2 to 7 days. PLease read the latest Tropical Weather
Outlook at website:
https://www.nhc.noaa.gov/cyclones/?atl for more details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis near 32W from
05N to 19N. This wave crosses a 1010 mb low (Invest AL99). It is
moving westward around 10 kt. Please read the Special Features
section above about the convection.

A central Atlantic tropical wave has its axis extending from
22N50W to near 07N55W. It is moving westward at around 15 kt.
Clusters of numerous moderate to strong convection have increased
during the overnight hours from 11N to 19N between the wave and
58W. Environmental conditions appear conducive for further
development of this system, and a tropical depression is likely to
form this weekend while it moves near or to the north of the
northern Leeward Islands.

A central Caribbean tropical wave is along 73W extending from
Haiti to inland northeastern Colombia. It is moving westward
at about 15 kt. Scattered showers and thunderstorms are noted
within 60 nm east of the wave from 09N to 10N.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic near the coastal border of
Western Sahara and Mauritania, then curves southwestward through
Invest AL99 as mentioned in the Special Features section and
northwestward to near 15N37W. Aside from convection associated to
Invest AL99, numerous moderate to isolated strong is evident from
09N to 13N between the coast of Africa and 20W.

...GULF OF AMERICA...

A weak pressure pattern over the area is generally maintaining
light to gentle winds and 1 to 2 ft seas.

For the forecast, a weak pressure pattern will continue over the
area through the period maintaining relatively quiet marine
conditions. Moderate to locally fresh northeast to southeast winds
will be possible over the south-central Gulf each afternoon and
evening through this weekend as a trough develops over the Yucatan
Peninsula and moves westward.

...CARIBBEAN SEA...

A subtropical ridge building south of Hurricane Erin in the
northwestern Atlantic is resuming a trade-wind flow across much
of the Caribbean Sea. Fresh to locally strong easterly winds and
5 to 7 ft seas are evident at the south- central basin. Moderate
to fresh northeast to east and seas of 4 to 6 ft is noted across
the north- central and eastern basin. Gentle to moderate NE to SE
winds and seas at 2 to 4 ft prevail for the rest of the basin,
including the Gulf of Honduras.

Scattered to numerous showers and thunderstorms are confined to
the southwestern section of the seas south of 11N between the
coast of Colombia and 82W. This activity is being enhanced by the
eastern extension of the East Pacific monsoon trough.

For the forecast, the aforementioned subtropical ridge will
maintain fresh to locally strong trades and moderate seas for the
central and eastern basin tonight through Fri. Elsewhere, fresh to
occasionally strong E to SE winds will pulse in the Gulf of
Honduras beginning tonight. Long-period northerly swell from
Hurricane Erin will begin to impact the Tropical North Atlantic
Offshore Zones from late Fri through Mon. Looking ahead, a
shower and thunderstorm activity has become a bit more
concentrated in association with a tropical wave located a few
hundred miles east of the Leeward Islands. Environmental
conditions appear conducive for further development of this
system, and a tropical depression is likely to form this weekend
while it moves near or to the north of the northern Leeward
Islands.

...ATLANTIC OCEAN...

Please see the Special Features section for information on
Invest Area AL99.

Hurricane Erin is well north of the area near 34.2N 72.1W at
21/0900 UTC, or about 180 nm ESE of Cape Hatteras, North Carolina.
It is moving NNE at 15 kt and the estimated minimum central
pressure has risen slightly to 945 mb. Maximum sustained winds are
90 kt with gusts to 110 kt. Seas 8 ft or greater are covering
much of the western Atlantic waters north of 23N and west of 65W.
Since Erin has a large cyclonic circulation, periphery tropical
storm force winds extend south of 31N to near 30N between 65W and
73W. Seas with these winds are in the 15 to 24 ft range. Outside
the direct influence of Hurricane Erin, fresh to near- gale SW to
W winds and 10 to 16 ft seas in large swell from Erin are present
north of 25N between 55W and 76W. Otherwise, a subtropical ridge
near 26N is supporting gentle to moderate southeast to south winds
and seas of 4 to 7 ft dominate north of 24N between 35W and the
Florida/southern Georgia coast. For the tropical Atlantic from 10N
to 24N between 35W and the Bahamas/Lesser Antilles, gentle to
moderate with locally fresh NE to SSE winds and 6 to 8 ft seas
exist. For the rest of the Atlantic Basin west of 35W, gentle to
moderate with locally fresh south to southwest winds and seas of
5 to 7 ft in mixed moderate swells prevail.

For the forecast, Erin will will continue to pull NNE far away
from the region through the end of the week while slowly weakening.
The tropical storm force winds currently affecting the waters
roughly north of 30N and between 65W and 73W will shift north of 31N
by early this afternoon. Associated seas will slowly subside today
through Fri. In addition, long period northerly swells generated by
Erin will affect just about the entire forecast area through the
next few days. In the wake of Erin, central Atlantic high pressure
will build WSW toward the central Bahamas and the Straits of Florida
through the period. Looking ahead, a tropical wave located several
hundred miles east of the Leeward Islands is producing a broad area
of disorganized showers and thunderstorms. Environmental conditions
appear conducive for gradual development of this system, and a
tropical depression is likely to form by this weekend while it moves
near or to the north of the northern Leeward Islands.

$$
Aguirre