447
AXNT20 KNHC 181802
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 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 1200 UTC surface analysis and satellite imagery through
1740 UTC.

...SPECIAL FEATURES...

Central Atlantic Ocean Significant Swell Event:
A 1008 mb low pressure center is near 27N52W. A stationary front
passes through 31N36W, to the 27N52W low pressure center, to
25N57W, beyond 31N65W. Moderate to rough seas are from the
stationary front northward between 50W and 60W, and from 30N
northward from 60W westward. Precipitation: scattered moderate to
widely scattered strong is from 24N northward between 40W and 53W.
Expect for the next 24 hours or so: strong to near gale-force NE
to E winds, and rough to very rough seas, are from 27N northward
between 44W and 57W. Expect elsewhere to the north of the line
31N45W 27N46W 24N55W 29N60W 31N58W: fresh to strong winds, and
rough seas in N to NE swell.

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 Atlantic Ocean tropical wave is along 31W/32W, from 20N
southward, moving westward 05 knots to 10 knots. Precipitation:
rainshowers are possible within within 120 nm on either side of
the tropical wave.

A Caribbean Sea tropical wave is along 81W/82W, from 20N
southward, moving westward 05 knots to 10 knots. Precipitation:
scattered to numerous moderate to strong is from 11N to 13N
between 78W and 81W. Widely scattered moderate to isolated strong
is from 12N to 15N between the tropical wave and 86W in Nicaragua
and in Honduras. Isolated moderate to locally strong is in the
remainder of the area that is between the 81W/82W tropical wave
and the southern Mexico tropical wave.

A tropical wave is moving through the Isthmus of Tehuantepec of
southern Mexico. The wave is moving westward 05 knots to 10 knots.
The monsoon trough is along 09N/10N between 73W at the border of
Venezuela and Colombia, beyond Costa Rica, into the Pacific
Ocean. Precipitation: scattered to numerous moderate to strong is
in the Pacific Ocean from 06N to 08N between the tropical wave and
85W, to the south of Panama and Costa Rica.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of Senegal
near 14N17W, to 12N3W 12N45W. Precipitation: isolated moderate to
locally strong is in the remainder of the area that is from 20N
southward from 60W eastward.

...GULF OF MEXICO...

The surface barometric pressure pattern is flat and weak. A middle
level to upper level trough is in the eastern half of the Gulf of
Mexico. Precipitation: isolated moderate to locally strong is to
the east of the line that runs from SE Louisiana and the SW corner
of the Gulf.

Moderate or slower winds, and slight seas, cover the entire area.

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...

Precipitation: isolated moderate is from 16N southward between 60W
and 70W. The SW part of the surface trough that is associated with
the 21N49W remnants of Gordon 1009 mb low pressure center.

Strong easterly winds are from 15N southward between 69W and 74W.
Fresh easterly winds are in much of the rest of the central one-
third of the area. Fresh anticyclonic wind flow is from 13N to 16N
from 80W westward. Moderate or slower winds are in the remainder
of the Caribbean Sea. Moderate seas are from 80W eastward. Slight
seas are in the remainder of the Caribbean Sea.

The 24-hour rainfall totals in inches, for the period that ended
at 17/1200 UTC, are: 0.34 in Merida in Mexico; 0.24 in Veracruz in
Mexico; 0.17 in Curacao; 0.11 in St. Thomas in the Virgin Islands;
0.04 in Guadeloupe. This information is from the Pan American
Temperature and Precipitation Tables/MIATPTPAN.

A weak pressure gradient across the Caribbean Sea will support
moderate to fresh winds and moderate seas across the E and central
Caribbean, and light to gentle winds and slight to moderate seas
across the NW and SW 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 tropical cyclone formation in
the next seven days.

...ATLANTIC OCEAN...

Please, read the Special Features section, for details about the
Central Atlantic Ocean Significant Swell Event/the 1008 mb low
pressure center that is near 27N52W.

A stationary front passes through 31N77W, to the NE coast of
Florida near 29N. Precipitation: widely scattered moderate to
isolated strong is from 29N northward between 67W and 72W.
Isolated moderate is elsewhere from 70W westward. The 24-hour
rainfall totals in inches, for the period that ended at
18/1200 UTC, are: 0.18 in Bermuda; and 0.07 in Nassau in the
Bahamas. This information is from the Pan American Temperature
and Precipitation Tables/MIATPTPAN.

The remnants of Gordon are a 1009 mb low pressure center that is
near 21N49W. A surface trough extends from the low pressure
center, to 14N55W and 12N65W. Moderate seas are within 500 nm of
the center in the E semicircle. Slight to moderate seas are within
600 nm of the center in the W semicircle. Precipitation: isolated
moderate to locally strong is from 12N to 20N between 40W and 60W.

A 1015 mb high pressure center is near 25N68W.

Slight seas are mostly from 11N northward 32W eastward.
Moderate seas, and moderate or slower winds, are in the remainder
of the Atlantic Ocean that is away from the remnants of Gordon,
and away from the area of the 27N52W 1008 mb low pressure center.
An exception is for fresh SE winds from 02N southward between 34W
and 40W; and for NE winds from 03N southward between 43W and land.

A non-tropical low pressure system located just E of the forecast
area is producing fresh to strong winds and building seas of 8 to
11 ft across the NE waters, particularly N of 25N and E of 60W.
These marine conditions will persist today and Thu, and gradually
diminish on Fri. Expect pulsing fresh trades off the coast of
Hispaniola through tonight. Otherwise, gentle to moderate winds
and slight to moderate seas will prevail across the rest of the
basin.

$$
mt/gr