Tropical Weather Discussion
Issued by NWS
AXPZ20 KNHC 062138
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue Dec 6 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
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 10N85W to 11N90W to 08N98W
to 11N104W. The ITCZ axis continues from 11N104W to 11N112W to
08N140W. Scattered moderate isolated strong convection is within
60 nm either side of a line from 13N113W to 08N127W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Gulf of California: A surface trough extends across northern
waters from 32N115W to 25N110W. Moderate southerly flow is
expected southeast of the trough to 29N, with strongest winds
near Isla San Luis. A weak cold front is expected to cross the
gulf Wednesday. Light and variable winds will prevail south of
29N through Wednesday, becoming northwesterly behind the front.
Fresh northwest flow is expected behind the front on Thursday,
except locally strong in the central and southern gulf waters.
Gulf of Tehuantepec: Gentle southerly flow will become northerly
in nocturnal drainage flow late tonight, and Wednesday night.
High pressure building over southern Mexico behind a strong cold
front Thursday night will induce northerly winds in the Gulf of
Tehuantepec to rapidly increase to gale force early Friday, then
continue through Saturday night. Max seas will build to 16-18 ft
downstream from the Tehuantepec coast.
Elsewhere, a ridge will meander across the area from 22N120W to
18N103W through Friday. Gentle to moderate anticyclonic flow is
forecast south of 20N through the weekend. Seas will gradually
subside to 3-5 ft through Friday morning.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: Fresh nocturnal offshore flow will resume
Wednesday night and Thursday night, increasing and becoming
strong Friday night and Saturday night.
Mostly light to gentle northerly winds with combined seas of 4-6
ft are occurring elsewhere north of 09N, while light to moderate
southwest flow is observed south of 09N. Combined seas of 3-4 ft
in mixed long-period northwest and southwest swell is expected
REMAINDER OF THE AREA...
A surface ridge extends southeast from 31N131W to 20N110W. High
pressure center will drift southeast into north central waters
near 29N123W late Wednesday night, and strengthen to block the
eastward advance of an approaching cold front, causing it to
stall from 32N137W to 31N140W Thursday.
Moderate to locally fresh northwest flow is expected northeast
of the ridge this week. Moderate to fresh trade winds south of
the ridge will weaken tonight and Wednesday, then increase a bit
Thursday night and Friday north of the ITCZ. Combined seas of 7
to 8 ft in mixed northeast winds waves and northwest swell north
of the ITCZ will gradually subside to 5-7 ft by Wednesday night.