AXPZ20 KNHC 280237
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Fri Oct 28 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 0000 UTC surface analysis and satellite imagery through
Tropical Storm Seymour continues to rapidly weaken, and is now
located near 22.0N 123.0W at 0300 UTC, moving north at 9 kt.
Estimated minimum central pressure is 1000 mb. Maximum sustained
winds are 40 kt with gusts to 50 kt. A small area of convection
is within 120 nm northeast of the center. Seymour will continue
to rapidly weaken overnight, becoming a post-tropical cyclone by
Friday afternoon, and dissipate by Sunday. See the latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25.
Gulf of Tehuantepec Gale Warning...a high pressure ridge across
eastern Mexico continues to produce a tight pressure gradient
across southeast Mexico. As a result, strong northerly winds
will continue to blow across the Gulf of Tehuantepec and spill
downstream for the next two days, pulsing to minimal gale force,
with the strongest winds occurring during the overnight and
early morning hours. Seas will build to 12 or 13 ft during the
periods of gale force winds.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 09N85W to 08N102W to 10N119W,
then resumes from 14N126W to 10N137W. ITCZ extends from 10N137W
to 10N140W. Minimal convection associated with the convergence
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
See special features section for details on a persistent Gulf of
Tehuantepec high wind event. Gentle to moderate anticyclonic
winds prevail across waters offshore of the Baja California
peninsula. Winds will slowly diminish this weekend, as a dying
cold front moves east and the pressure gradient weakens. 5 to 7
ft seas in NW swell will subside to 4 to 5 ft this weekend, then
build to 6 to 9 ft by Sunday as another cold front and a new
pulse of northwest swell moves across the northern waters.
In the Gulf of California, gentle to moderate northerly flow
will prevail today, with winds becoming light and variable by
early Friday as an elongated northwest to southeast trough sets
up across the gulf. Low pressure is forecast to develop in the
far northern Gulf of California by early Sunday. Winds southeast
of the low are forecast to increase to fresh to strong Sunday,
pulsing through early next week. Seas will be 2 ft or less
across the northern gulf through the weekend, building to 4 to 7
ft as the winds increase, with 2 to 4 ft seas expected over the
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gentle to moderate west to southwest winds are found south of
the monsoon trough, while gentle west to northwest winds prevail
north of the trough. Latest altimeter data shows seas ranging
between 4 to 6 ft, primarily in long period southwest swell. Seas
will decay to 3 to 4 ft this weekend.
REMAINDER OF THE AREA...
A surface low north of the area located near 32N126W trails a
cold front extending south-southwest from the low to 26N127W to
17N140W. Moderate to fresh northwest winds are behind the front
and northwest swell supports seas to 10 ft. Gentle to moderate
southwest winds are present ahead of the front. The front will
weaken as the low moves further north of the area Friday. NW
swell will continue to propagate southeastward, and mix with
seas generated by Seymour, resulting in an area of confused seas
between 118W and 126W through Friday night. Another cold front
will reach the area late Friday, bringing a reinforcing pulse of
large northwest swell. Moderate to fresh trades will prevail
outside the front and the remnant low of Seymour, with combined
seas of 4 to 6 ft.