AXPZ20 KNHC 290943

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
658 UTC Mon Aug 29 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 0000 UTC surface analysis and satellite imagery through
0900 UTC.


Lester makes a comeback and becomes a major hurricane. At 29/0900
UTC, it is centered near 18.0N 127.8W moving west or 270 degrees
at 13 kt. Estimated minimum central pressure is 965 mb. Maximum
sustained wind speed is 100 kt with gusts to 120 kt. Lester is a
category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.
Little change in strength is expected today, but slow weakening is
expected to begin by Tuesday. Lester is forecast to cross 140W
and move into the central Pacific basin by Wednesday night while
continuing on a westward motion. Numerous moderate to strong
convection is seen within 75 NM of center. Numerous moderate to
isolated strong convection is elsewhere within 120 nm of center.
See latest NHC forecast/advisory under AWIPS/WMO headers
MIATCMEP3/WTPZ23 KNHC for more details.


The monsoon trough axis extends from 10N90W to low pressure near
12N113W to 13N120W. A cluster of moderate to strong convection is
near 07.5N83W. Scattered moderate and isolated strong convection
is within 75 nm of the coast of Central America between 85W and
90W. Scattered moderate convection is from 09N to 11N between 96W
AND 99W, and from 09N to 11N between 104W AND 106W.



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 through
Tuesday. By Tuesday night into Wednesday, marine guidance suggests
building seas to 8 in northwest swell across the western part of zone
PMZ011. Expect light and variable winds in the Gulf of California
through the next several days with seas of 2 ft or less. Farther
south, winds will be mainly gentle to moderate and west-northwest
with combined seas of 4 to 6 ft. Pulsing moderate to locally
fresh northerly winds are expected across the Gulf of Tehuantepec
during the overnight and early morning hours through Thursday.


Gentle to moderate SW winds will prevail S of the monsoon trough
with mainly light to gentle variable winds N of it. Long period
cross equatorial SW swell will continue to dominate the area with
seas of 4 to 7 ft.


Hurricane Madeline is west of 140W, however, winds of 20 to 25 kt
and seas to 9 ft continue to impact the area from 15N to 19N W of
138W. These marine conditions will gradually diminish over the
next 12 hours as Madeline continues to move farther west of the
area. Seas generated by hurricane Lester will reach the west-
central waters later today.

A broad surface ridge covers most of the northern waters,
extending from 1023 mb high pressure near 33N130W. A weak surface
trough persists across the NW part of the forecast area and extends
from 30N136W to beyond 24N140W. A recent Ascat pass continues to
show the wind shift associated with this trough. 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 9 to 12 feet.

Weak low pressure of 1010 mb remains embedded in the monsoon
trough near 12N113W. Convection has increased in association with
this system over the past 24 hours. Satellite imagery shows
scattered moderate to isolated strong convection from 10N to 13N
between 112W and 115W. 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 south of
the low pressure. Marine guidance suggests that an area of fresh
to strong southwest to west winds will persist S of the low
center over the next 48 hours, with seas building to 8 to 10 ft by
Tuesday night.