000
AXPZ20 KNHC 170935
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
407 UTC Sat Sep 17 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 0600 UTC surface analysis and satellite imagery through
0830 UTC.

...SPECIAL FEATURES...

Post-Tropical Cyclone Orlene is centered near 20N128W. Maximum
sustained winds are 30 kt with gusts to 40 kt. The low level
circulation remains fully exposed and lacks deep convection.
Orlene is forecast to continue heading W and weakening during the
next several days, then dissipate on Monday. See final NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC
for more details.

Broad low pressure 1007 mb centered near 13N106W has a high
probability of becoming a tropical cyclone during the next 48
hours. Scattered moderate isolated strong convection is present
from 10N to 18N between 100W and 112W. A gale warning is in effect
for Sunday, in anticipation of increased winds associated with an
intensifying low. See the latest high seas forecast under
AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 09N84W to 11N91W to 15N100W to
1007 mb low pres near 13N106W to 12N109W to 11N129W. The ITCZ
continues from 11N129W to beyond 09N140W. Scattered moderate
isolated strong convection is seen from 10N to 18N between 88W and
100W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A surface ridge extends from 32N137W to W of the southern tip of
Baja California near 22N118W. The ridge is maintaining moderate
NW winds W of Baja California and seas of 4 to 6 ft. Winds will
briefly diminish, with gentle to moderate winds prevailing W of
Baja California tonight. A surface trough over the Baja peninsula
will maintain light to gentle winds in the Gulf of California
through the weekend. The low pressure area centered near 13N106W
will move NW and become better organized the next couple of days,
producing gale force winds in portions of the offshore zones W of
Cabo Corrientes and S of Cabo San Lucas Sunday. The gales are
expected to continue as this system becomes a tropical cyclone and
tracks NNW parallel to coast of southern Baja California.

In the Gulf of Tehuantepec, fresh to strong N winds will pulse
during the overnight and early morning hours Sunday through
Wednesday.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...

Light to gentle winds are expected through early next week N of
05N. Mainly moderate SW to W winds are expected over waters S of
05N. Combined seas of 4 to 6 ft are likely across the entire area
through the weekend into next week as long period cross-
equatorial SW swell propagate northeastward. Scattered showers
and isolated thunderstorms are possible at night over the offshore
waters.

REMAINDER OF THE AREA... 

The ridge over the northern waters will primarily generate fresh
trades through Saturday N of 14N and W of 128W. This will support
8 to 9 ft seas from 10N to 20N W of 130W through Saturday. Winds
and seas will diminish Sunday as the ridge weakens in response to
a cold front approaching the NW United States. Strong winds and
large swell are likely over the open Pacific waters W of the Baja
offshore zones Sunday through Tuesday.

$$
cam