000
AXPZ20 KNHC 180300
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sun Sep 18 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
0300 UTC.

...SPECIAL FEATURES...

Tropical Depression Seventeen-E near 16.7N 110.0W at 0300 UTC
moving NW at 14 kt. Minimum sea level pressure is 1005 mb.
Maximum sustained winds are 30 kt with gusts to 40 kt. The
depression is expected to move northwest and intensify into a
tropical storm through Monday, then weaken north of 23N. See
latest NHC forecast/ advisory under AWIPS/WMO headers
MIATCMEP2/WTPZ22 KNHC for more details.

...TROPICAL WAVES...

A tropical wave along 94W north of 07N is moving west at 10 to
15 kt. It is the same tropical wave which spawned TS Ian in the
Atlantic last week. Isolated moderate convection is noted within
45 nm of the wave axis. 

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

The monsoon trough extends from 09N83W to 09N93W, then continues
from T.D. 17-E near 17N110W to 12N115W to 10N140W. Scattered
moderate convection within 30 nm north of the trough axis west
of 130W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A ridge extends west of the offshore waters off the coast of
Baja California reaching near the Revillagigedo Islands. The
pressure gradient between this ridge and troughing over the Gulf
of California is maintaining gentle to moderate winds over the
offshore waters of the Baja California Peninsula. T.D. 17-E is
forecast to move west of the Baja California Peninsula within a
few days...and parallel the coast afterwards. Tropical storm
conditions may reach extreme western portions of the offshore
zones west of Baja Peninsula Sunday night through Monday night.

The tropical wave discussed above will enhance northerly winds
in the Gulf of Tehuantepec during late night and early morning
hours tonight. Winds will continue to pulse the next few days as
high pressure builds over the Gulf of Mexico and tightens the
gradient between the area of high pressure and lower pressure
associated with the monsoon trough. Winds will reach near 25 kt
during the overnight hours.

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

Moderate to occasionally fresh winds are expected north of the
monsoon trough. Gentle to moderate southwest winds are expected
south of the trough axis. Combined seas of 4-6 ft will prevail
in long period cross-equatorial SW swell through mid-week.

REMAINDER OF THE AREA... 

High pressure northwest of the area near 35N147W extends a ridge
southeast to near 19N111W. The gradient between this ridge and
the remnant circulation of Orlene centered near 20N132W supports
20-25 kt winds northwest of the center. The circulation will
weaken to a trough and move west of 140W in about 48 hours. An
altimeter pass earlier showed seas to 10 ft north of the low.
Seas will continue to subside during the next two days as the
low disappears and pressure gradient continues to weaken.

$$
Mundell