168
AXPZ20 KNHC 241600
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Tue Sep 24 2024

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1530 UTC.

...SPECIAL FEATURES...

Tropical Storm John is centered near 17.7N 100.5W at 24/1500
UTC, moving northwest at 10 kt. Estimated minimum central
pressure is 1001 mb. Maximum sustained wind speed is 35 kt with
gusts to 45 kt. Scattered moderate to strong convection is
occurring within 80 NM south of the center, with additional
bands of convection occurring within 250 NM to the south of the
center. Little motion is expected during the next few days, and
slow weakening is expected. John will remain inland and weaken to
a tropical depression near 17.7N 101.1W this evening, 17.3N
101.1W Wed morning, 17.1N 100.8W Wed evening, inland to 17.4N
100.7W Thu morning, inland to 17.7N 100.8W Thu evening, and
dissipate Fri morning. Through Thursday, Tropical Storm John is
expected to produce 6 to 12 inches of rain with isolated totals
around 15 inches across the coastal areas of Chiapas. In areas
along and near the Oaxaca coast to southeast Guerrero, between 10
and 20 inches of rain with isolated totals near 30 inches can be
expected through Thursday. Swells associated with John are
forecast to continue affecting the coast of southern Mexico
during the next day or so, with the potential for dangerous surf
and rip currents. Please see local statements for more
information.

Please read the latest HIGH SEAS FORECAST issued by the National
Hurricane Center at website -
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest
John NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

A Central American Gyre will continue to produce periods of
excessive rainfall over southern Mexico and Central America for
the remainder of the week, as well as the adjacent western
Caribbean and eastern Pacific waters between 80W and 95W. This
scenario, combined with daytime heating and orographic lifting,
could produce dangerous flash flooding and mudslides across the
area. Furthermore, strong to near gale force winds, rough seas
and heavy thunderstorms are forecast to affect the offshore
waters between Costa Rica and El Salvador through the end of the
week. Please follow the forecasts from your local weather offices
for more detailed information.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough axis extends from 14N108W to 14N121W to
12N140W. Aside from convection related to John and the Central
American Gyre, scattered moderate to locally strong convection is
noted from 08N to 11N west of 136W. Scattered moderate
convection is seen within 120 NM south of the trough between 112W
and 133W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please refer to the Special Features section above for
information on Tropical Storm John and on the Central American
Gyre (CAG).

A 1021 mb high pressure is centered near 34N143W, a trough
extends through Baja California into western Mexico, and Tropical
Storm John is centered over Guerrero. This pattern supports
gentle to moderate NW winds and seas of 4-5 ft across the Mexico
offshore waters, and light to gentle winds and seas of 1-3 ft in
the Gulf of California. Farther south, fresh to strong W to SW
winds are occurring along the outer periphery of John, generally
south of 15N and between 95W and 104W. Seas of 8 to 12 ft are
likely occurring in this area, with locally higher seas up to 14
ft in the area of strongest winds.

For the forecast away from Tropical Storm John, fresh to strong W
to SW winds will continue through Fri, mainly south of 16N
between 95W and 105W. Winds will slowly diminish below strong
speeds on Sat, and diminish further on Sun. Periods of near gale
force winds will be possible today into Thu. Rough to locally
very rough seas are expected off the coast of Guerrero through
Oaxaca through at least Fri, before slowly subsiding this weekend
into early next week. Elsewhere, moderate to locally fresh NW
winds and moderate seas will occur across the rest of the Mexico
offshore waters through this weekend, with the exception of the
Gulf of Mexico, where winds will remain light to gentle.

...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...

Please refer to the Special Features section above for
information on the Central American Gyre (CAG).

Moderate to fresh SW winds are occurring over the offshore
waters of Central America, while moderate SW winds are noted off
the coast of Colombia and Ecuador. Seas of 6 to 9 ft are
occurring off the coast of Guatemala southeastward toward
Nicaragua, while the rest of the offshore waters are likely
seeing seas of 4 to 7 ft. Scattered moderate to strong convection
is noted north of 06N and east of 93W to the coast of Central
America. Strong winds and rough seas will occur near convection.

For the forecast, moderate to fresh SW winds will continue in
the wake of Tropical Storm John off the coast of Guatemala
southeastward toward Nicaragua through at least Wed night, with
fresh winds continuing near Guatemala into the weekend. Rough
seas will also occur in this region, with seas slowly subsiding
in the coastal waters off of Nicaragua by Wed night, and off the
coast of Guatemala Fri into Sat. Periods of strong convection
will also occur over most of the Central America offshore waters
through the rest of the week.

...REMAINDER OF THE AREA...

Fresh to strong SW winds and rough seas continue north of 09N and
east of 111N. Elsewhere, moderate to locally fresh SW winds are
occurring south of the monsoon trough from 06N to 13N east of
134W. North of the monsoon trough, gentle to moderate N to NE
winds prevail.

For the forecast, moderate to fresh SW winds will continue in
the wake of Tropical Storm John north of 09N and east of 111W
through Fri, with winds slowly diminishing through this weekend.
Rough to locally very rough seas will also occur in this area,
subsiding late this weekend into early next week. Elsewhere,
moderate to fresh SW winds will continue south of the monsoon
trough through late week.

$$
ADAMS