AXPZ20 KNHC 281444

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1444 UTC Sun Aug 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
meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1430 UTC.


Hurricane Lester is centered near 18.1N 123.7W at 28/1500 UTC
moving west or 270 degrees at 11 kt. Estimated minimum central
pressure is 979 mb. Maximum sustained wind speed is 75 kt with
gusts to 90 kt. Little change in strength is expected through
the week. Lester is forecast to cross 140W and move into the
central Pacific basin by Thursday while continuing on a westward
motion. Numerous moderate and isolated strong convection is within
120 NM in the southeast semicircle, and within 90 nm in the
northwest semicircle. See latest NHC forecast/advisory under
AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details.


The monsoon trough axis extends from 10N89W to 13N105W to low
pressure near 11N112W to 14N119W. Scattered moderate and isolated
strong convection is within 60 nm southwest of the axis between
97W and 102W, within 180 nm either side of the axis between 107W
and 119W, and also within 150 nm southwest of a line from 11N133W
to 15N135W to 15N139W.



A ridge dominates the waters off Baja California producing
moderate to locally fresh northerly winds and seas generally under
6 ft. Little change in this weather pattern is expected over the
next 48 hours. By Tuesday night, marine guidance suggests building
seas to 8 to 9 ft in northwest swell across zone PMZ011. Expect
light and variable winds in the Gulf of California through the
next several days. Farther south, winds will be mainly light to
moderate and west-northwest with combined seas of 4 to 6 ft.
Active convection in the Gulf of Tehuantepec in the form of
scattered moderate and isolated strong, extending within 150 nm
northwest of a line from 16N93W to 12N9W, will gradually diminish
through the day.


Light and moderate winds will continue to prevail on either side
of the monsoon trough for the next several days, with combined
seas of 4 to 7 ft mainly in cross equatorial southerly swell.


Tropical Storm Madeline is west of 140W, however, winds of 20 to
30 kt continue to impact the area from 15N to 19N west of 139W. A
large area of mixed swell covers the surrounding waters from
roughly 13N to 22N west of 134W. These conditions will gradually
diminish and subside through Monday as Madeline continues to move
farther west of the area.

A broad surface ridge covers most of the northern waters,
extending from 1021 mb high pressure near 31N130W. A weak surface
trough extends from 29N136W to 23N140W, and will cross 140W by
Monday morning. Scattered showers and isolated thunderstorms are
occurring in the vicinity of this feature. The pressure gradient
between the ridge and Lester will produce a band of moderate to
fresh winds roughly from 20N to 25N, with combined seas ranging
from 6 to 9 feet.

Weak low pressure of 1011 mb remains embedded in the monsoon
trough near 11N112W. Associated convection remains disorganized
and is described in the monsoon trough section above. Tropical
cyclone formation is forecast to remain low through the next
several days as it tracks westward along the monsoon trough.
Scatterometer data show moderate to fresh southwesterly monsoon
flow into the monsoon trough west of the low pressure. Marine
guidance suggests fresh to strong southwest to west winds mainly
south of the low center from 07N to 13N between 106W and 131W,
through early Tuesday, with seas building to 8 to 10 ft on Monday.