Tropical Weather Discussion
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AXPZ20 KNHC 091526

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1526 UTC Fri Dec 9 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 1200 UTC surface analysis and satellite imagery through
1430 UTC.


Gulf of Tehuantepec Gale Warning: The gale began earlier this
morning over the Gulf with seas likely building above 10 ft late
this morning. The gradient will continue to tighten this evening
and tonight as sustained winds increase to around 45 kt. Max seas
will build to 16-18 ft by early Saturday. Gale conditions will
persist until 1200 UTC on Sunday, then pulse to 25-30 kt each
night from Sunday night through Tuesday night.


The monsoon trough axis extends from 09N84W to 08N100W to
07N109W. The ITCZ continues from 07N109W to 08N130W to beyond
09N140W. Scattered moderate convection is present from 06N to 13N
between 94W and 115W, as well as from 06N to 11N between 115W and



Gulf of California: The pressure gradient between surface
troughing along the Mexico coast and high pressure over the east
Pacific will continue to support fresh to strong northwest winds
over the Gulf of California mainly south of 28N through late this
evening. Then, the pressure gradient will relax somewhat with
winds decreasing to moderate to fresh late tonight. The area of
high pressure to the northwest will weaken late Saturday, allowing
for gentle to moderate winds to prevail Saturday night through

A gale over the Gulf of Tehuantepec will continue until Sunday
morning. Please see the special features section above for more
details. Elsewhere, ridging dominates the offshore Pacific waters
of Mexico with a 1026 mb high centered near 29N126W. Aside from
the Tehuantepec event, light to gentle winds will prevail south
of 17N through the forecast period. Fresh to occasionally strong
northwest winds west of Baja California will continue through
Sunday night before decreasing to moderate to fresh as the ridge
weakens slightly. From 17N north to Mazatlan, moderate to locally
fresh northwest winds will prevail.


Gulf of Papagayo: Fresh to strong offshore winds east of 90W will
continue to pulse mainly during the overnight hours this weekend.
Seas will top out around 8 ft during these pulsing events. A
surface trough over the central Caribbean will cross Central
America early Monday. Some of the global guidance indicates
possible low pressure development along the trough axis as it
moves westward from zones PMZ113 to PMZ111 on Tuesday and

Mostly light to gentle N to NE winds, and combined seas of 3 to 5
ft, are occurring elsewhere N of the monsoon trough, which is
expected to meander between 07N and 10N through Wednesday. Light
to moderate southwest flow is observed from 05N to 09N, with
combined seas of 3 to 5 ft in southwest swell. Moderate to fresh
southerly flow is expected south of 05N through Wednesday.


1026 mb high pressure is centered near 29N126W with a ridge axis
extending southeast from the high to near 15N105W. Gentle to
moderate north-northwest flow is expected northeast of the ridge
axis this weekend and moderate to fresh trades will prevail south
of the ridge and ridge axis, north of the ITCZ. Fresh to
occasionally strong NE winds and combined seas of 8 to 9 ft will
generally prevail from 07N to 17N W of 120W north of the ITCZ
through Sunday. Low pressure approaching the eastern Pacific from
the northwest will weaken the ridge on Tuesday and Wednesday,
allowing winds and seas in this area to subside.

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