Tropical Weather Discussion
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085
AXPZ20 KNHC 181522
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sat Oct 18 2025

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
1500 UTC.

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

The monsoon trough extends from the coast of Panama near 09N84W
to a 1008 mb low pres near 13N99W to 09N135W. ITCZ continues from
that point to beyond 08N140W. Scattered moderate to isolated
strong convection is noted N of 09N between 87W and 105W.
Similar convection is noted from 07N to 12N and west of 125W.

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

The combination of the proximity of the monsoon trough and a
broad area of low pressure located south of southern Mexico is
producing scattered showers and thunderstorms, especially north
of 08N and between 90W and 106W. A recent scatterometer
satellite pass indicate that moderate to fresh winds are
occurring in these waters. Moderate seas prevail in this area.
In the remainder of the Mexican offshore waters, a weak pressure
gradient dominates, supporting moderate or weaker winds and
slight to moderate seas.

For the forecast, moderate or weaker winds will prevail across
the offshore waters of Baja California through early next week. A SW
swell will bring rough seas to the N Baja California waters Sun
through early Mon, while another long-period swell will reach the
area late Mon. Winds will freshen up and seas build to rough midweek
through late next week. Moderate NW winds are forecast in the
central and southern Gulf of California this evening through Mon. At
the same time, fresh NW winds will pulse across the waters of Cabo
Corrientes. Strong to near gale-force NE gap winds and rough
seas are expected in the Gulf of Tehuantepec Mon and continue
pulsing through next week.

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

Scattered showers and thunderstorms along the monsoon trough
prevail over the offshore waters of Central America producing
heavy downpours, gusty winds and higher seas. A recent
scatterometer satellite pass captured gentle to moderate
southerly winds south of the monsoon trough. Moderate seas are
noted in these waters. Elsewhere, light to gentle winds and
moderate seas prevail.

For the forecast, moderate SW winds and moderate seas will occur
south of the monsoon trough into early next week, with gentle
winds and moderate seas prevailing to the north.

...REMAINDER OF THE AREA...

Latest satellite-derived wind data indicate that the subtropical
ridge positioned well northwest of the region supports moderate
to fresh NE winds north of 10N and west of 130W. Seas in these
waters are in the rough range. Meanwhile, moderate to fresh
southerly winds and moderate seas are occurring south of the
monsoon trough. Elsewhere, moderate or lighter winds and moderate
seas are prevalent.

For the forecast, moderate to fresh NE winds and rough seas will
occur north of the monsoon trough into this weekend as high
pressure prevails to the north. Winds will diminish slightly for
the second half of the weekend. A new SW swell will support rough
seas north of 25N through Sun. A tightening pressure gradient
will support fresh to strong winds and rough seas near westward-
moving low pressure along the monsoon trough Sun through late
next week. Moreover, increasing winds and building seas are
expected over the northern waters early next week as a weakening
cold front moves southward along the Mexican coast.

$$
ERA