674
AXPZ20 KNHC 260350
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Thu Sep 26 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 0000 UTC surface analysis and satellite imagery through
0330 UTC.

...SPECIAL FEATURES...

Tropical Storm John is centered near 17.0N 102.1W at 26/0300
UTC, moving northwest at 4 kt. Estimated minimum central pressure
is 984 mb. Maximum sustained wind speed is 55 kt with gusts to
65 kt. The 12 ft seas extend 300 nm within the SE quadrant and
240 nm in the SW quadrant with peak seas near 18 ft. Numerous
moderate to strong convection is noted from 13N to 19N between
100W and 106W. John will continue moving slowly NW over the next
day or two, followed by a gradual turn to the west- northwest on
Friday. On the forecast track, the center of John is forecast to
approach the southwestern coast of Mexico on Thursday and be
inland on Friday. John is forecast to strengthen to a hurricane
by early Thursday, with additional strengthening expected until
the center moves inland.

Through Friday, Tropical Storm John is expected to produce
additional rainfall amounts of 10 to 20 inches with isolated
totals around 30 inches across portions of the Mexican States of
Guerrero, Oaxaca and Michoacan. Swells associated with John are
forecast to continue to affect the coast of southern and
southwestern Mexico through the week, 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 Guatemala 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 extends west of Tropical Storm John from
13N110W to 12N130W to beyond 10N140W. Aside from the convection
related to Tropical Storm John and the Central American
Gyre, scattered moderate convection is noted from 10N to 14N
between 111W and 120W and from 08N to 13N between 129W and 140W.

...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).

Lower pressure over Mexico and Tropical Storm John along with
ridging extending over the Baja California offshore waters is
supporting moderate to fresh NW winds over waters N of 20N. Seas
are 6 to 8 ft within mostly NW swell. Light to gentle breezes
and seas of 1-3 ft prevail in the Gulf of California. For the
waters S of 18N and E of 105W, strong to near gale force winds
are occurring along the periphery of Tropical Storm John. Winds
are light to gentle near the Gulf of Tehuantepec, increasing to
strong S of 14N. Seas are 8 to 12 ft in the waters E of 98W.

For the forecast, Tropical Storm John is near 17.0N 102.1W at 8
PM PDT, and is moving northwest at 4 kt. Maximum sustained winds
are 55 kt with gusts to 65 kt, and the minimum central pressure
is 984 mb. John will strengthen to a hurricane near 17.3N 102.3W
Thu morning, move to 17.7N 102.5W Thu evening, inland to 18.1N
102.7W Fri morning, move inland and weaken to a tropical
depression near 18.4N 103.2W Fri evening, and dissipate Sat
morning. Rough to very rough seas will impact the south and
southwest Mexico offshore waters through Sat. Moderate to fresh
winds will continue over the Baja California offshores through
the weekend, with rough seas subsiding by Sun night.

...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 locally fresh W to SW winds are occurring over the
coastal waters from Guatemala through Nicaragua, and seas of 6 to
11 ft are noted in this area. Gentle to moderate S to SW winds
and seas of 4 to 7 ft within S to SW prevail elsewhere. Scattered
moderate convection is noted across the Costa Rica and Panama
offshore waters. Locally strong winds and rough seas will occur
near convection.

For the forecast, moderate to fresh SW winds will continue
across the offshore waters of Nicaragua tonight, and persist
across the waters of El Salvador and Guatemala through Fri.
Moderate to rough seas will accompany these winds, with seas
slowly subsiding Sat night. Elsewhere, gentle to moderate SW
winds will continue into early next week. Scattered to numerous
showers and thunderstorms will continue over most of the offshore
waters through the rest of the week.

...REMAINDER OF THE AREA...

Strong to near gale force winds are occurring along the
periphery of Tropical Storm John, generally north of 10N and east
of 109W. Seas of 8 to 14 ft are likely occurring in this region.
Moderate to locally fresh SW winds are noted south of the
monsoon trough east of 120W and south of 10N. Elsewhere, gentle
to moderate N to NE winds prevail north of the monsoon trough
with seas of 4-7 ft. In the far northwest waters, N of 23N and W
of 128W, NW swell is bringing seas 8 to 9 ft seas.

For the forecast, strong to near gale force winds will continue
north of 09N and east of 114W through Fri before winds slowly
diminish through Sat. Rough to very rough seas will accompany
these winds, with seas slowly subsiding this weekend into early
next week. Elsewhere, a building NW swell will lead to seas of 8
to 9 ft north of 22N and west of 125W through Thu. Fresh winds
along the monsoon trough will also bring rough seas between 120W
and 130W.

$$
AReinhart