AXPZ20 KNHC 060915
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Wed Dec 6 2023
Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.
Based on 0600 UTC surface analysis and satellite imagery through
Gulf of Tehuantepec Gale Warning: Strong high pressure stretches
over central Mexico, supporting northerly gale force winds
across the Gulf of Tehuantepec. This pattern will persist
through Thu. Seas expected to reach 8-11 ft through this period,
peaking to 12 ft on Thu morning. Seas are expected to completely
subside below 8 ft by Fri.
Please read the latest High Seas Forecast issued by the National
Hurricane Center at
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 09N84W to 06N102W. The ITCZ
extends from 06N102W to 11N116W, then resumes W of a trough along
120W near 08N120W to beyond 08N140W. Scattered moderate
convection is noted from 05N to 16N between 104W and 134W.
...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Please read the Special Features section for more information on
the Gale Warning in the Gulf of Tehuantepec.
A broad ridge extends across the offshore waters of Baja
California from 1022 mb high pressure near 30N127W to Cabo San
Lazaro, Mexico. The pattern is supporting gentle northerly winds
across most of the Baja California offshore waters with moderate
winds across Baja California Sur offshore waters. Moderate to
fresh N to NW winds prevail over the Gulf of California. NW swell
across the Baja California Norte waters is bringing 8 to 9 ft
seas mainly over the waters beyond 60 nm north of Cabo San
Lazaro. Seas range 3 to 4 ft across the Gulf of California.
Farther south, gentle to moderate breezes persist off southern
Mexico with 4 to 6 ft combined seas in mixed swell.
For the forecast, outside of the gap winds in the Gulf of
Tehuantepec, long-period NW swell will persist off Baja
California and the Revillagigedo Islands through Sat. Seas as
high as 12 ft could move across the Baja California Norte waters
tonight. Reinforcing NW swell will arrive off Baja California
Norte by Thu night into Fri, accompanying a decaying cold front
moving into the region. Swells will subside later in the weekend.
Strong winds could develop across most of the Gulf of California
this weekend, producing rough seas.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...
Fresh to strong NE to E winds prevailing across the Gulf of
Papagayo, where seas are near 5 to 7 ft. An earlier
scatterometer pass confirmed these winds, and gentle to moderate
winds elsewhere over the region. Seas range 5 to 7 ft in the
Guatemala and El Salvador offshore waters mostly within N to NW
swell due to the influence of the Gulf of Tehuantepec gap wind
event. Elsewhere, seas range 4 to 6 ft seas primarily in S to SW
swell. Scattered showers and thunderstorms are noted south of
the monsoon trough off the coast of W Colombia.
For the forecast, high pressure north of the region will support
pulsing strong winds across the Gulf of Papagayo at night
through the rest of the week. Seas will build well offshore of
Guatemala through Thu due to swell generated by gale-force gap
winds in the Gulf of Tehuantepec. Gentle to moderate winds are
forecast elsewhere. Moderate combined seas will persist through
the rest of the week in a mix of SW and NW swell.
...REMAINDER OF THE AREA...
High pressure dominates the waters north of 20N. Fresh to strong
trade winds persist south of the ridge, mainly 07N to 23N west
of 115W. Seas in this region are 8 to 12 ft, in a mix of seas
due to the trade wind flow, and long-period NW swell. A cold
front stretches in the NW corner of the basin from 31N135W to
27N140W with moderate to fresh winds in its vicinity. A large
reinforcing NW swell is bringing 12 to 16 ft seas N of 23N and W
of 130W. Combined seas of 8 to 10 ft cover much of the region
elsewhere W of 115W, although with primarily S to SE swell S of
05N. Gentle to moderate winds and 4 to 7 ft seas are noted east
of 115W. A sfc trough is analyzed along 120W between 10N and
15N with scattered moderate convection.
For the forecast, the high pressure will dissipate today as the
cold front continues its movement to the E across the waters
N of 25N through Thu. This will allow for trade winds to
diminish slightly W of 115W today. Large, long-period NW swell
accompanying the front will continue to move across the waters N
of 10N and W of 120W through Thu supporting seas to 16 ft today N
of 20N and W of 130W. E of 115W, the combination of the NW swell
with shorter-period NE swell emerging from gap wind events and
fresh E trade winds will support rough seas from 07N to 12N
between 95W and 110W from Thu into Fri.