Skip Navigation Links
NOAA NOAA United States Department of Commerce

Eastern North Pacific Tropical Weather Discussion

AXPZ20 KNHC 042145

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2145 UTC Sun Dec 4 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 1800 UTC surface analysis and satellite imagery through
2130 UTC.


The monsoon trough axis extends from 10N86W to 09N93W to 10N103W
to 09N125W. The ITCZ reaches from 09N125W to 10N140W. Scattered
moderate convection is noted within 90 nm north of the monsoon
trough between 115W and 125W. Scattered moderate to isolated
strong convection is also noted from 11N to 13N between 110W and



Gulf of California: Strong northwest winds and 5 to 7 ft seas
currently to the north of 27N will diminish/subside to a fresh
breeze later this afternoon and further diminish to a moderate to
fresh breeze tonight. Light to gentle southerly flow is expected
north of 29N on Monday, with light and variable winds forecast
across the Gulf waters south of 29N. The next cold front is
expected to pass across the northern gulf on Wednesday, with fresh
to locally strong post-frontal flow forecast on Wednesday night.

Moderate to fresh northwest to north winds persist off Baja California,
along with 7 to 9 ft seas in northwest swell. The pressure gradient
will gradually slacken through Tuesday allowing for the winds to
diminish to a gentle to moderate northerly breeze on Monday, with
combined seas in the 4 to 6 ft range, except for higher seas of 7
to 9 ft in northwest swell north of 26N around Guadalupe Island
Monday and Tuesday.

Farther south, jet dynamics aloft continue to support scattered
showers and thunderstorms off the coast of Mexico, along a
persistent surface trough from 17N101W to 11N103W. The showers and
thunderstorms are moving onshore between Petatlan and Acapulco.
The trough is forecast to gradually shift east- southeast through
the next couple of days while weakening.

Gulf of Tehuantepec: The next strong gap wind event is expected
to begin beyond 48 hours early on Thursday afternoon. Northerly
winds across the Gulf will quickly strengthen to minimal gale
force late Thursday afternoon, with the gale conditions possibly
increasing to strong gale winds through early on Saturday. Along
with these winds, seas are forecast to rapidly build to large
heights of around 17 to 21 ft.


Gulf of Papagayo: Moderate to locally fresh nocturnal northeast
to east winds are expected to begin again late Tue night. 

Light to gentle northerly winds, except for light and variable
winds to the east of 100W are present elsewhere north of the
monsoon trough, with seas in the 4 to 6 ft range. A gentle to
moderate southwest flow is observed to the south of the monsoon
trough, with seas in the 5 to 6 ft in long-period southwest.


A ridge extends from 1030 mb high pressure near 36N135W to 18N115W
near Clarion Island. The high pressure is support a broad area of
moderate to fresh trade winds from roughly 10N to 25N west of
125W. A recent altimeter pass confirmed 8 to 10 ft seas, likely
due to long period northwest swell lingering over the area. The
high will weakens ahead of a deep low pressure system moving from
north of Hawaii toward the Pacific Northwest region over the next
several days. Trades winds will diminish further through mid week
as the high pressure weakens. The northwest swell will likewise
decay below 8 ft over most of the area through mid week. 

Meanwhile scattered showers and thunderstorms persist along to the
north of the monsoon trough between 115W and 125W, enhanced in
part by jet dynamics aloft.