363
AXNT20 KNHC 202228
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat Sep 21 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 1800 UTC surface analysis and satellite imagery through
2200 UTC.

...SPECIAL FEATURES...

Potential Heavy Rainfall in Central America: Latest satellite
imagery shows scattered to numerous moderate to strong
convection associated with a developing Central American Gyre
(CAG), over the W Caribbean W of 76W. This activity is expected
to persist through this weekend and into the middle of next week
while moving northwestward, becoming focused in El Salvador,
Guatemala, and southern Mexico by late next week. The heaviest
rainfall is expected along the south and west coasts of Mexico,
Guatemala, El Salvador, Nicaragua, and Costa Rica. Heavy rainfall
will lead to increased potential for life-threatening flash
flooding and mudslides in these areas. It is recommended that
residents in the aforementioned areas stay alert on the latest
information from their meteorological agencies. Please refer to
the Tropical Weather Discussion for the Eastern Pacific at
website:
https://www.hurricanes.gov/text/MIATWDEP.shtml for more details on
rainfall across the Pacific coastal areas of these nations.

...TROPICAL WAVES...

A tropical wave has its axis near 89W, from 20N southward, moving
W at 10 kt. Scattered moderate convection is noted near the
northern portion of the wave axis, generally from 18N to 21N
between 86W and the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the basin from the west coast of Africa
near 11N16W and continues westward to near 08N38W. The ITCZ then
stretches from 08N38W to near 10N46W. Scattered moderate
convection is noted from 04N to 09N and E of 25W.

The East Pacific monsoon trough also extends across the southwest
Caribbean to inland Colombia. Convection in this area is
associated with a developing Central American Gyre, see the
SPECIAL FEATURES section above for more details.

...GULF OF MEXICO...

A diurnal surface trough is analyzed over the Bay of Campeche
along 92W, with scattered showers developing along and near the
northern portion of the trough axis. Another surface trough is
noted over the SE Gulf along 24N and E of 85W with no notable
convection nearby. Otherwise, high pressure of 1013 mb centered
near 29N94W is dominating Gulf weather, bringing dry conditions,
light to gentle winds, and seas of less than 3 ft.

For the forecast, moderate to locally fresh winds may pulse in
the eastern Bay of Campeche nightly through the next several days.
Looking ahead, a broad area of low pressure could form by the
early to middle part of next week over the northwestern Caribbean
Sea. Thereafter, gradual development of this system is possible,
and a tropical depression could form as the system moves slowly to
the north or northwest over the northwestern Caribbean Sea and
into the southern Gulf of Mexico through the end of next week.
There is a medium chance of tropical cyclone formation in the next
seven days. Regardless of development, winds and seas will start
increasing across the SE Gulf early next week.

...CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section above for details on
convection in the southwest Caribbean associated with a developing
Central American Gyre (CAG).

Convergent surface winds are leading to the development of
scattered showers and isolated thunderstorms in the far eastern
Caribbean. Otherwise, moderate to fresh easterly winds and seas
at 3 to 5 ft are evident in the central basin. Gentle to moderate
SE to E winds and 2 to 4 ft seas are seen across the remainder of
the basin.

For the forecast, moderate to fresh winds and moderate seas are
expected across the E and central Caribbean through at least
Sat. Looking ahead, a broad area of low pressure could form by
the early to middle part of next week over the northwestern
Caribbean Sea. Thereafter, gradual development of this system is
possible, and a tropical depression could form as the system moves
slowly to the north or northwest over the northwestern Caribbean
Sea and into the southern Gulf of Mexico through the end of next
week. There is a medium chance of tropical cyclone formation in
the next seven days.

...ATLANTIC OCEAN...

A surface trough that extends roughly along the Gulf Stream
offshore Florida is inducing scattered moderate convection in its
immediate vicinity. An upper-level trough is also helping to
generate areas of scattered moderate convection over and to the
northeast of the Bahamas and the Turks and Caicos Islands. A 1006
mb area of low pressure centered near 25N55W. Another low is
centered near 26N43W. A surface trough connects both lows along
25N between 40W-63W. Scattered moderate convection prevails along
the trough. To the north of these features, moderate to fresh E
winds generally north of 26N between 52W and 58W, along with seas
of 8 to 9 ft in this area. Environmental conditions do not appear
conducive for significant development of any of these systems
during the next couple of days while it drifts northwestward at
about 5 kt over the central or western subtropical Atlantic.
Elsewhere, light to gentle winds and seas at 4 to 7 ft dominate
most of the basin.

For the forecast W of 55W, a weak cold front will move off the SE
coast of the US tonight and slowly move across the waters N of
25N through Mon. Fresh NW winds and moderate seas will prevail
along and W of the front.

$$
ERA