AXPZ20 KNHC 280939
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 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
Based on 0600 UTC surface analysis and satellite imagery through
Hurricane Lester is centered near 17.9N 122.2W at 28/0900 UTC
moving west or 270 degrees at 12 kt. Estimated minimum central
pressure is 978 mb. Maximum sustained wind speed is 85 kt with
gusts to 105 kt. Little change in strength is expected today, but
slow weakening should begin by Monday. Numerous moderate scattered
strong convection is within about 75 nm of center. Scattered
moderate convection is noted elsewhere within about 90 nm of
center. Lester will continue on a general westward motion, with an
increase in forward speed during the next couple of days. See
latest NHC forecast/advisory under AWIPS/WMO headers
MIATCMEP3/WTPZ23 KNHC for more details.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 11N90W to 12N102W to low
pressure near 10.5N111W to 12N114W. Scattered moderate isolated
strong convection is from 09N to 13N between 111W and 116W.
Scattered moderate convection can be found from 10N to 12.5N
between 105W and 108W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
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
8-9 ft in NW swell across zone PMZ011 and regional waters. Expect
light and variable winds in the Gulf of California through the
next several days. In the Gulf of Tehuantepec, moderate to
occasionally fresh northerly winds and seas of 4-6 ft are
expected during the overnight and early morning hours through
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA,
COLOMBIA, AND WITHIN 750 NM OF ECUADOR...
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 has crossed into the central Pacific
basin. At 28/0900 UTC, Madeline is centered near 16.1N 140.6W
moving NW or 305 degrees at 7 kt. Estimated minimum central pressure
is 998 mb. Maximum sustained wind speed is 50 kt with gusts to
60 kt. Fresh to strong winds in the 20-30 kt range and seas up to
14-16 ft, associated with Madeline, continue to affect the west-
central waters, particularly from 14N to 17N W of 138W. Winds
will gradually diminish today into Monday as Madeline continues to
move away from the forecast area. However, seas will briefly
subside through Monday, then increase again as tropical cyclone
Lester approaches the west-central waters.
A broad surface ridge covers most of the north waters, extending
from 1021 mb high pressure near 31N130W. A weak surface trough
extends from 28N136W to 20N139W, and will cross 140W tonight. The
0614 UTC Ascat pass shows the wind shift associated with the
trough S of 26N. Isolated showers and thunderstorms are associated
with 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.
A weak low pressure of 1012 mb remains embedded in the monsoon
trough near 10.5N111W. Scattered moderate isolated strong convection
is noted mainly west of the center from 09N to 13N between 111W
and 116W. 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 SW to W winds
mainly S of the low center from 08N to 11N between 110W and 117W
tonight through Monday night, with seas building to 8 to 10 ft on