305
AXNT20 KNHC 181027
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Sep 18 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
1000 UTC.

...SPECIAL FEATURES...

Central Atlantic Ocean Significant Swell Event: A 1007 mb non-
tropical low pressure center is near 28N51W. A cold front extends
from the low center to 23N57W, followed by a stationary front to
31N65W. A warm front extends from the low center to 27N48W,
followed by a stationary front to 31N36W. Strong to near gale NE
to E winds and seas of 12 ft and greater are occurring within 240
NM to the west and north of the center. Peak seas are around 16
ft. Numerous moderate and scattered strong convection is noted
north of 26N between 41W and 51W. The system will gradually weaken
as it moves slowly toward the southwest Wed and Thu. Winds will
diminish and seas will subside below 12 ft by Thu night.

Please see the latest NWS High Seas Forecast issued by the
National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further
details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is along 30W, south of 20N,
moving westward at 5 kt. A few showers are found near the trough
axis.

A central Caribbean tropical wave is along 80W, south of 20N,
moving westward at 5-10 kt. A few showers and isolated
thunderstorms are seen near the trough axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic near 14N17W through the
coast of Senegal and continues west-southwestward to 11N28W and
then to 15N43W. Only isolated showers are noted along the trough
axis.

...GULF OF MEXICO...

Generally dry conditions prevail over much of the Gulf of Mexico.
A few showers and isolated thunderstorms are evident in the
eastern Bay of Campeche as storms that occurred over western
Yucatan overnight move westward. A persistent weak pressure
gradient across the Gulf supports moderate or weaker winds and
slight seas.

For the forecast, weak surface ridging over the Gulf waters will
support light to gentle winds and slight seas across much of the
basin into Thu. Moderate winds may pulse in the Bay of Campeche
nightly through Fri. A cold front moving through the NE Gulf will
lead to moderate NE winds across the basin Thu through Fri. Little
change is expected on Sat.

...CARIBBEAN SEA...

A sharp upper level trough over the SE United States continues to
enhance the development of showers and isolated thunderstorms
over the NW Caribbean. A few showers are also seen in the eastern
Caribbean. A broad ridge to the north of the islands forces
moderate to fresh E winds and seas of 4-7 ft across the central
Caribbean and Gulf of Honduras. Elsewhere, moderate or weaker
winds and slight to moderate seas prevail.

For the forecast, moderate to fresh E winds and seas of 4-6 ft
will continue into Thu morning across central and west-central
portions of the Caribbean as a tight pressure gradient between the
Colombian low and weak ridging in the southwestern Atlantic
prevails. For Thu through the weekend, moderate trades and slight
seas will occur across the central Caribbean, with light to gentle
winds occurring across northwest and southwest portions of the
basin. Looking ahead, a broad area of low pressure could form this
weekend over the northwestern Caribbean Sea. Thereafter, some
slow development of this system is possible through early next
week while it moves slowly to the north or northwest over the
northwestern Caribbean Sea. There is a low probability of
formation in the next seven days.

...ATLANTIC OCEAN...

Please read the Special Features section for details about the
Central Atlantic Ocean Significant Swell Event.

A sharp upper level trough over the SE United States and abundant
moisture continues to support scattered showers and isolated
thunderstorms west of 69W and north of 22N. The rest of the SW
North Atlantic, west of 55W, is under the influence of a broad
subtropical ridge located in the NW Atlantic. This ridge forces
fresh to strong E trade winds south of 22N and between 69W and
73W. Seas in these waters are 4-6 ft. Elsewhere west of 55W
outside of the influence of the low pres near 28N51W, moderate or
weaker winds and moderate seas prevail.

A broad area of low pressure centered near 20N49W, the remnants
of Gordon, is producing disorganized showers and thunderstorms. A
surface trough extends from the low center to the Windward
Islands and scattered showers are observed near this boundary.
Moderate to locally fresh S winds and seas of 5-7 ft are
occurring from 17N to 24N and between 44W and 49W. The broad
subtropical ridge dominates the remainder of the tropical
Atlantic, sustaining moderate or weaker winds and moderate seas.

For the forecast, pulsing fresh trades off the coast of
Hispaniola will continue through Thu as a tight pressure gradient
between the Colombian low and weak ridging in the southwestern
Atlantic prevails. Otherwise, gentle to moderate winds and slight
to moderate seas will prevail across the rest of the basin.

$$
ADAMS