AXPZ20 KNHC 101445
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sat Dec 10 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
Gulf of Tehuantepec Gale Warning: The latest scatterometer
passes missed the western Gulf of Mexico and Gulf of
Tehuantepec, however, surface observations from Coatzacoalcos
Mexico have been consistently showing NW winds of around 30 kt
during the past several hours. A strong ridge of high pressure
over eastern Mexico is maintaining a tight pressure gradient
over the Isthmus of Tehuantepec. This gradient is expected to
support sustained winds to around 40 kt over the Gulf of
Tehuantepec today and tonight, then the gradient will slacken as
high pressure over the western Gulf of Mexico weakens and shifts
eastward. Seas will be peaking around 16 ft today, then will
subside below 8 ft Sunday night. Gale conditions will persist
until Sunday morning, then pulse between 20 and 30 kt each night
from Sunday night through Tuesday night.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 10N84W to 08N98W. The ITCZ
continues from 08N98W to 09N110W to 05N135W to beyond 06N140W.
Scattered moderate convection is from 08N to 13N between 103W
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Ridging dominates over the offshore waters of Mexico resulting
from 1025 mb high pressure centered near 28N129W. Aside from the
Tehuantepec high wind event, light to gentle winds will prevail
S of 17N through the forecast period. Fresh to occasionally
strong northwest winds west of Baja California will continue
through Sunday night, then become moderate to fresh as the ridge
weakens in response to low pressure approaching from the NW.
Between 17N and Mazatlan moderate to fresh northwest winds will
prevail through Tuesday night.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: Fresh to strong offshore winds east of 92W
will continue to pulse mainly during the overnight hours this
weekend. Max seas during this event will be around 9 ft. An
easterly wave over the central Caribbean will cross Central
America Monday. Some model guidance calls for low pressure
development along the wave axis as it moves westward away from
Costa Rica on Tuesday and Wednesday. Model guidance consensus
and climatology both suggest this system will remain a trough or
weak low during this time frame.
Light to gentle north to northeast winds and combined seas of 3
to 5 ft are occurring north of the monsoon trough, which is
expected to meander between 08N and 10N through Wednesday. Light
to moderate southwest winds are observed from 05N to 09N, with
combined seas hovering between 3 and 5 ft in southwest swell.
Moderate to fresh southerly flow is expected south of 05N through
REMAINDER OF THE AREA...
High pressure centered near 28N129W ridges southeast to near
19N109W. 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 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 122W through Monday
morning. Low pressure encroaching on the far northwest waters will
weaken the ridge and maintain a relatively light wind regime in
this area Tuesday through Friday.