989
AXPZ20 KNHC 240406
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 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 0000 UTC surface analysis and satellite imagery through
0345 UTC.

...SPECIAL FEATURES...

Major Hurricane John is centered near 16.3N 98.8W at 24/0300
UTC, moving north at 7 kt. Estimated minimum central pressure is
959 mb. Maximum sustained wind speed is 105 kt with gusts to 120
kt. Seas are in the 12 to 19 ft range. Latest satellite imagery
shows John is continuing to intensify as noted by the presence of
an eye feature that is surrounded by a solid thick ring of very
cold cloud top numerous strong convection. This convection is
within 120 nm of the center in the E semicircle, also within 90
nm of the center in the SW quadrant and within 60 nm of the
center in the NW quadrant. Similar convection is seen from 16N to
19N between 100W and 104W. Numerous moderate to isolated strong
convection is from 12N to 15N between 96W and 102W. On the
current forecast track, the center of John is forecast to move
inland along the coast of southern Mexico in the next couple of
hours. John will continue to move inland over southern Mexico on
Tue. John is now a category 3 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Some additional strengthening is possible
the next couple of hours before John makes landfall. After
landfall, the system will rapidly weaken over the high terrain of
southern Mexico. Hurricane 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 Thu.
Swells associated with John are forecast to continue affecting
the coast of southern Mexico during the next couple of days, with
the potential for dangerous surf and rip currents much of the
week. 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 generate periods of excessive
rainfall over southern Mexico and Central America this 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 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 14N110W to 14N123W to
10N129W to 12N140W. Aside from convection related to John and
the Central American Gyre, scattered moderate convection is
seen within 120 nm south of the trough between 110W and 113W.

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

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

A high pressure ridge extends southeastward from a 1023 mb high
center that is located well northwest of the area to near
25N125W. The gradient between it and relatively lower pressure
in northwest Mexico is allowing for generally gentle to moderate
northwest to north winds to exist over the offshore waters. Light
to gentle northwest winds are over the Gulf of California. Seas
are 1 to 3 ft over the Gulf, except for higher seas of 3 to 5 ft
at the entrance to the Gulf. Fresh to near strong winds are
likely occurring in the periphery of Hurricane John with seas of
8-10 ft.

For the forecast aside that described above for Hurricane John,
high pressure will maintain generally gentle to moderate
northwest to north winds over the offshore waters. Winds are
forecast to increase to fresh speeds over most of the offshore
waters starting Wed, with little change expected going into the
early part of the upcoming weekend.

...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 southwest winds are over the offshore waters
of Central America north of Guatemala while gentle to moderate
winds are elsewhere. Seas are 6 to 9 ft in west swell over
the offshore waters of Guatemala. Seas are 4 to 7 ft over the
remainder of the offshore waters.  Moderate to strong convection
is occurring from 05N to 10N between 81W and 90W, including in
the waters off the coasts of Panama and Costa Rica. Strong winds
and rough seas will occur near convection.

For the forecast, moderate to fresh southwest winds will
continue in the wake of major Hurricane John off the coast of
Central America through north of Guatemala through Wed night.
West to northwest swell will propagate generally eastward in the
wake of John, through the waters of Guatemala tonight, expanding
farther east toward El Salvador on Tue, and toward Nicaragua Wed.
Periods of strong convection will also occur over most of the
Central America offshore waters through at least through Wed.

...REMAINDER OF THE AREA...

The gradient related to high pressure ridging over the area is
supporting moderate to fresh northeast winds west of about 130W,
and gentle to moderate winds east of 130W. Seas are 6 to 8 ft
with these winds. Elsewhere, fresh to locally strong southwest
winds continue south of the monsoon trough east of 125W and
north of 09N.

For the forecast, SW winds become well established south of the
monsoon trough as the trough slowly lifts northward over the next
few days. Fresh to strong SW winds will occur generally north of
09N and east of 110W through Wed, with strong southwest winds
continuing east of 105W through at least Fri. Rough seas will
accompany these gusty winds. Looking ahead, a trough of low
pressure located several hundred miles southwest of southwestern
Mexico is producing disorganized showers and thunderstorms.
Development of this system is no longer expected as it moves
eastward towards the coast of southern Mexico the next few days.

$$
Aguirre