000
AXPZ20 KNHC 090914
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
459 UTC Mon Jan 9 2017

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
0900 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: Based on the most recent ASCAT
scatterometer passes, the storm warning has been downgraded to a
gale warning over the Gulf of Tehuantepec. The strong high
pressure center responsible for the tight pressure gradient over
the forecast area has shifted eastward. This has loosened the
pressure gradient enough over the forecast waters to diminish
winds over the Gulf of Papagayo to 45 kt. The high will slowly
shift northeastward into the north Atlantic waters over the next
day. This will further diminish the pressure gradient over the
forecast waters with winds expected to diminish below gale force
Tuesday night. A large area of NE swell generated by this gap wind
event will propagate far from its source region west to 120W, and
south of the equator over the next couple of days.

Gulf of Papagayo Gale Warning: A tight pressure gradient between
high pressure centered north of the area and low pressure within
the monsoon trough has increased winds funneling into the Gulf of
Papagayo. These gradient winds, with the added component of
nocturnal drainage flow has helped winds reach minimal gale force
over the Gulf of Papagayo. Winds may diminish briefly below gale
force early this evening but are once again expected to ramp up
to gale force late tonight into early Tuesday. Winds are then
expected to diminish below gale force Tuesday afternoon. Seas will
build to 11-13 ft later today and remain 9-12 ft downwind from the
Papagayo gap through midweek.

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

The monsoon trough extends from 08N83W to 04N95W. The ITCZ continues
from 04N95W to 09N130W to low pressure near 07N135W to beyond
07N140W. Scattered moderate convection is noted from 05N to 10N
between 128W and 135W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see special features section for more details on the Gulf
of Tehuantepec gale force gap wind event.

A weak pressure gradient prevails over much of the remaining
forecast region. Light to gentle winds with 3-5 ft seas prevail
off the coast of the Baja California peninsula and along the
southwest coast of Mexico. Northwest swell will propagate into
the waters offshore of Baja California Norte Wednesday night,
increasing seas to 10 ft by early Thursday morning.
  
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...

Please see special features section for more details on the Gulf
of Papagayo gale force gap wind event.

The tight pressure gradient responsible for the Gulf of Papagayo
gale force winds will support fresh to strong northeast winds
northwest of Nicaragua, including the Gulf of Fonseca, through
midweek.

In the Gulf of Panama and near the Azuero Peninsula, northerly
winds have increased to 20-25 kt overnight as strong winds have
started to funnel into the area from the southwest Caribbean.
Winds are expected to remain fresh to strong through midweek
before diminishing. Seas will build to 8-10 ft south of the
peninsula by early Tuesday.

The combined swell generated from the Gulf of Papagayo and Gulf
of Tehuantepec gap wind events will generate a large area of 8
ft or greater seas that will extend from the Tehuantepec and
Papagayo regions southward to near the equator and westward to
near 120W by late Tuesday.

REMAINDER OF THE AREA...

A large occluded low pressure system north of the area extends a
cold front through 30N125W to 21N132W. Weak high pressure is
centered east of the cold front near 27N121W. High pressure has
built in the wake of the cold front, centered just west of the
area near 28N142W. The height rises behind the front have helped
loosen the pressure gradient over the northern waters and winds
have diminished well below advisory criteria as depicted in the
most recent ASCAT pass. The low pressure area well north of the
area will continue to generate pulses of moderate to large
northwest swell which will propagate into the northwest waters
with seas building above 8 ft over the northwest waters today.

The combination of swell generated from the Gulf of Papagayo and
Gulf of Tehuantepec gap wind events has generated an east to
northeasterly swell that is propagating from the area. This swell,
with seas greater than 8 ft, will move across the waters roughly
from 05N to 15N through the week.

High pressure building across the northern waters through the week
will freshen trades north of the ITCZ. The large fetch of these
fresh winds will help generate seas building to near 8 ft over
the far western waters north of the ITCZ by midweek.

$$
AL