AXPZ20 KNHC 242140
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2115 UTC Wed Aug 24 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 1800 UTC surface analysis and satellite imagery through
Tropical Depression Thirteen-E has developed and was centered
near latitude 15.2 North, longitude 109.9 West. The depression is
moving toward the west- northwest near 12 kt. Maximum sustained
winds are near 30 kt with gusts to 40 kt with an estimated minimumcentral
pressure of 1006 mb. Scattered to locally numerous moderate to
strong convection was noted within 240 nm in the NE and within 120
nm in the SW semicircles. The tropical depression is forecast to
strengthen during the next 48 hours, and is expected to become a
tropical storm tonight.
A large and complex tropical wave is along about 130W, moving
westward at 10 to 15 knots. The associated moisture and convection
spans the area along the monsoon trough between 122W and 132W. An
elongated 1007 mb surface low has become better defined during the
day and is located near 12N125W. Scattered moderate to strong
convection is occurring from 09N to 14N between 123W and 131W. A
broad zone of fresh easterly trade winds prevails north of the low
from about 13N to 17N between 118W and 129W, where seas are
running 6-8 ft. Environmental conditions are conducive for a
gradual improvement in organization of this system, and it has a
medium chance for tropical cyclone development within the next 48
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from low pressure near 09N75W to
10N85W to 08N95W to 10N102W. The ITCZ begins near 11N135W and
extends through 10N140W. Widely scattered to scattered moderate
to strong convection is occurring within 90 nm S of the trough
between 88W and 95W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A narrow surface ridge extends from the NE Pacific southeastward
through 30N125W to near Las Islas Tres Marias. This ridge will
change little during the upcoming weekend, and combine with the
persistent trough meandering along the Baja California peninsula
and Gulf of California to produce mainly light to moderate
northerly flow prevailing outside of the Gulf of California.
Expect mainly light to gentle southerly flow In the Gulf of
California, except for occasionally fresh wind flow in the
northern Gulf where the pressure gradient will be slightly
Very active convection associated with tropical depression
thirteen-E continues over PMZ015 and PMZ023 will move west of the
area late tonight and Thursday. However, lines and bands of
moderate to strong convection described above were still within 75
nm of the coast of Mexico offshore of Manzanillo. East to
northeast winds of 15-20 kt occurring across the waters this
morning will gradually diminish tonight and become light and
variable as a weak ridge builds across the area behind the exiting
High pressure across the Gulf of Mexico continues to drive
northerly winds across the Gulf of Tehuantepec, which had
increased to 25-30 kt early this morning, with seas 6-9 ft.
these winds will remain 20-25 kt in a narrow plume, and increase
slightly again late tonight before diminishing to 15-20 kt by
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Moderate to locally fresh offshore winds are expected across
most of the area e of 95W and north of the monsoon trough today,
with strongest winds 15-20 kt across the Gulf of Papagayo
region. Winds are expected to become light and variable late
Thursday into Friday, except for 15-20 kt offshore winds across
Papagayo, then become onshore at 10 kt or less over the weekend.
The weak center center of the post-tropical remnant low of Kay
is a 1014 mb low pressure center near 24N124.5W. No deep
convective precipitation is present with the low pressure center.
The remnant low will continue to move west- southwestward, and
gradually dissipate into an open trough. A broad area of 20 kt NE
winds with seas 6-8 ft in found within 120 nm across the NW
semicircle of the low.
A broad high pressure ridge dominates the remainder of the area,
extending from a large 1037 mb high across the NE Pacific. As
the low center along 122W and associated tropical wave move
westward during the next few days, the pressure gradient between
the monsoon trough and the ridge will yield freshening winds
across the trade wind belt, generally south of 21N, from just
northeast of the low center to beyond 140W. Seas of 6-8 ft in
this area in mixed swell will increase slightly to 7-9 ft during
this time. South of the monsoon trough, a large area of fresh
southwesterly monsoonal flow is supporting seas of 8 to 9 ft
north of 07N between 115W and 125W. The strength and areal
coverage of these fresh winds will increase south and southeast
of the low as it shifts westward over the next few days, and act
to increase seas to 6-8 ft in mixed south and southwest swell.