Eastern Pacific Tropical Discussion

Active Tropical Systems Basin Outlooks Satellite
Eastern Pacific Basin Tropical Discussion
 
795 
AXPZ20 KNHC 300926
TWDEP 

Tropical Weather Discussion 
NWS National Hurricane Center Miami FL 
1005 UTC Sat Jul 30 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... 

An area of low pressure is embedded along the monsoon trough
near 12.5N116.5W with an estimated minimum central pressure of
1008 mb, moving west-northwest at 10 kt. Widely scattered to
scattered moderate to strong convection was noted from 08.5N to
14N between 113W and 122W associated with this elongated
circulation. Recent scatterometer data indicate an elongated
circulation with  winds 20 kt or less, while seas remain less
than 8 ft. Conditions are forecast to become more conducive for
development of this low over the next few days, and it has a
medium chance of tropical cyclone formation through the next 48
hours.

...TROPICAL WAVES...

A tropical wave is along 96W and is moving west at 10 to 15 kt.
Widely scattered to scattered moderate to strong convection is
occurring within 150 nm north and 180 nm so of the monsoon
trough in the vicinity of this wave, as well as behind the
wave along the coast of central America.

..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from low pressure near 09.5N75W to
11N90W to 09N102W to low pressure near 12.5N116.5W to 10N124W.
The ITCZ extends from 10N124W to beyond 08N140W. Scattered to
numerous moderate to strong convection is noted north of 05N and
east of 80W. Widely scattered to scattered moderate to strong
convection is noted from 06N to the coast between 81W and 91.5W.
Scattered moderate to strong convection is noted within 150 nm
north and 180 nm south of the trough between 91W and 102W.
Scattered moderate to strong convection is noted within 150 nm
north and 180 nm south of the trough and low between 108W and
123W. Scattered moderate to strong convection is noted within
150 nm north of the ITCZ westward of 133W.

Also, scattered moderate to strong convection is occurring
within 90 nm of the coasts of Mexico and Guatemala from the
Gulf of Tehuantepec to 91.5W.

...DISCUSSION...   

N of 15N E of 120W:

In the Gulf of California, surface troughing will linger along
the Baja California peninsula for the next few days. Moderate to
fresh south to southeasterly flow will prevail in the central
and northern Gulf on the east side of this troughing, with light
and variable winds across the southern Gulf. Winds in the
central and northern Gulf will diminish late in the weekend as
the pressure gradient relaxes.

Across the Gulf of Tehuantepec, nocturnal northerly flow has
increased to around 20 kt overnight, and will do so again
tonight, before diminishing during the daylight hours. This
nocturnal drainage flow is expected to become more pronounced
and increase to 20-25 kt each night, Sunday night through
Tuesday night. 

Elsewhere, A weak surface ridge extends into the area from the
northwest, partially disrupted by the remnant circulation of Frank
located well to the west. This ridging will support mainly gentle
west to northwest flow across the open Pacific waters,
occasionally pulsing to moderate just offshore of the Baja
California peninsula. Seas will remain in the 4 to 6 ft range.

S of 15N E of 120W: 

Across the Gulf of Papagayo, nocturnal drainage flow has pulsed
to fresh overnight and should continue into early this morning,
then will increase to fresh to strong late tonight into early
Sunday. Weaker winds are expected through the middle of next
week as the monsoon trough drifts slightly northward. Otherwise,
light to moderate flow is anticipated on either side of the
monsoon trough.

Long-period cross-equatorial southwesterly swell producing seas
of 6 to 9 ft, will gradually decay through the weekend. Broad
and weak low pressure is expected to develop near 09N101W this
evening, associated with the tropical wave along 96W currently.
This low will shift westward in tandem with the tropical wave
over the next few days, but recent model guidance suggesting it
weaken to a trough late Monday through Tuesday.

W of 120W:

Ridging extending from northwest of the area is disrupted by the
remnant circulation of Frank, currently near 24N127W. The
remnant of Georgette is has degenerated into an open trough
and moved west of 140W. 

Meanwhile, northwest swell of 8 to 9 ft in the far northwest
corner of the area earlier tonight has subsided to around 7 ft
in recent hours. A new pulse  of northerly swell will move south
of 30N late Sunday night through the early part of next week,
and raise seas to 7-8 ft west of 125W.

$$
Stripling