AXPZ20 KNHC 291508
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1509 UTC Fri Jul 29 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 1200 UTC surface analysis and satellite imagery through
Low pressure is embedded in the monsoon trough near 12.5N111.5W at
1009 mb, moving west-northwest at around 7 kt. Associated
convection has diminished during the past several hours. There
have been no recent scatterometer passes over the low, however,
winds are likely still 20 kt or less with seas also less than 8
ft. Conditions are forecast to become more conducive for
development, and this low has a medium chance of tropical cyclone
formation through the next 48 hours.
A tropical wave extends from 11N117W 1008 mb to 19N119W and is
moving west at 10 to 15 kt. Scattered moderate convection is
within 120 nm in the northwest semicircle of the low, with
limited convection elsewhere in the vicinity of the tropical wave.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 10N85W to 08N96W to low
pressure near 12.5N111.5W to low pressure near 11N117W to 10N125W.
The intertropical convergence zone axis extends from 10N125W to
07N140W. Scattered moderate convection is within 120 nm either
side of the axis between 89W and 103W, and also within 120 nm in
the northwest semicircle of the low near 11N117W.
Also, scattered moderate and isolated strong convection is from
03N to 07N east of 80W, just south of the Gulf of Panama. This
convection developed overnight over western Colombia before
N of 15N E of 120W:
In the Gulf of California, surface troughing will linger along the
Baja California peninsula. Moderate to fresh 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.
In the Gulf of Tehuantepec, nocturnal northerly flow will pulse to
fresh through Sunday, then will increase to fresh to strong Monday
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 be 4 to 6 ft.
S of 15N E of 120W:
In the Gulf of Papagayo, nocturnal drainage flow will pulse to
fresh levels tonight into early Saturday, then will increase to
fresh to strong late Saturday night 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 with seas of 6
to 9 ft, will gradually decay through the weekend. Weak low
pressure near 08N94W with fresh winds on the southeast side,
combined with the southwesterly swell is supporting combined seas
of 8 ft. Expect these seas to linger on the southeast side of the
low as it moves to the west around 10 to 15 kt for the next few
W of 120W:
Ridging extending from northwest of the area is disrupted by the
remnant circulations of Frank and Georgette. The remnant low of
Frank is near 24N126W at 1008 mb with associated winds now 20 kt
or less. Lingering combined seas to 8 ft on the western side of
the low will decay to less than 8 ft by early Saturday. The
remnant of Georgette is near 20.5N137W at 1014 mb, and will
become a remnant trough later today. Remnant seas of 8 to 9 ft
on the west side of the remnant will subside later today.
Meanwhile, northwest swells of 8 to 9 ft in the far northwest
corner of the area will subside by tonight with a new set of
northerly swell seeping south of 30N Sunday night through the
early part of next week.