AXPZ20 KNHC 011551
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sat Oct 1 2016
Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
Based on 1200 UTC surface analysis and satellite imagery through
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 08N76W to 09N87W to 08N102W to
12.5N114W to 09N126W to low pres near 09.5N139W. Scattered
moderate to strong convection is noted from 04N to 08.5N east of
84W. Scattered moderate to strong convection is noted within 210
nm N and 150 nm S of the monsoon trough between 85W and 110W.
Scattered moderate to strong convection is noted within 90 nm of
the monsoon trough between 122W and 130W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A weak pressure gradient remains over the forecast waters and is
supporting mainly light to gentle northwesterly winds across
much of the area. Northerly winds over the Gulf of Tehuantepec
pulsed to around 30 kt early this morning, with seas building to
7-10 ft, but haver since diminished slightly. A surface trough
extends from 15N113W to low pres near 17N114W to 22N114.5W,
where overnight scatterometer dated indicated winds in the
gentle to locally moderate range. Seas are generally 5-6 ft
outside the Gulf of California, and 2 ft or less across all but
the southern entrance to the Gulf of California. The surface
trough and low will continue to shift slowly westward away from
the forecast waters this weekend while weakening. Strong high
pressure across the NE Pacific will then build across the
northern waters through the weekend. This will tighten the
pressure gradient and freshen winds north of 28N by early next
week. Northerly swell will propagate into the far northern
waters off the coast of Baja California Norte, building seas to
8 ft tonight through Tue. Fresh northerly winds across the Gulf
of Tehuantepec will continue to pulse to 25-30 kt during the
next couple of nights.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Light and variable winds are expected north of the monsoon
trough, while gentle to locally moderate south to southwesterly
winds are expected south of the monsoon trough through the
upcoming weekend. Combined seas of 4 to 7 ft, primarily in long-
period southwesterly swell is expected across the offshore waters
through the next several days.
REMAINDER OF THE AREA...
High pressure will build over the northern waters this weekend which
will tighten the pressure gradient over the western waters between
the ridge and lower pressure within the monsoon trough. This
will freshen winds north of the monsoon trough this weekend, and
increase winds from 15N to 25N w of 120W to around 20 kt by Mon.
The long fetch of these fresh trades will help build seas to the
7-9 ft range early next week.