AXPZ20 KNHC 210745
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Tue Mar 21 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
Pacific Gale Warning for far northern waters behind a cold front:
A cold front analyzed from near 30N125W tot 22N140W. Strong high
pressure building in behind the front with cold-air advection
will lead to gale-force W to NW winds today north of about 29N
and between 130W-135W, with strong to near- gale force winds
north of 25N through tonight. As the front moves E away from the
area, winds will diminish below gale force by Wed.
Pacific Significant Swell Event: The other hazard from the
aforementioned cold front will be large NW swell following the
front, with seas reaching to 19 ft late today into early on Wed
north of 27N. Wave heights in excess of 12 ft will reach as far
south as 23N Wed before subsiding. Looking ahead, even as the NW
swell decays Thu into Fri, it will mix with increasing shorter-
period waves associated with northeast trade winds along with
combined significant wave heights reaching 12 ft mainly from 05N
to 25N and west of 110W.
Please read the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and Offshore
Waters Forecast at www.nhc.noaa.gov/marine/offshores.php for
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The ITCZ extends from 02N103W to 00N116W. Convection associated
with ITCZ has diminished overnight.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
The tight pressure gradient over southern Mexico resulting from
high pressure over the Gulf of Mexico is beginning to relax
early this morning as the high pressure moves E away from the
region. Thus, gales have ended in the Gulf of Tehuantepec. Strong
gap winds will gradually diminish into tonight, and seas will
fall below 8 ft.
Elsewhere off Mexico, weak high pressure dominates most of the
waters. Light to gentle winds are present over most of these
waters. Moderate to locally fresh SW winds are ongoing over the
northern Gulf of California, and winds well W of Baja California
Norte have recently increased to moderate to fresh. Seas are
generally 2 to 4 ft.
For the forecast, a cold front will cross Baja California and the
Gulf of California tonight into Wed. Fresh to strong SW to W gap
winds will develop in the northern Gulf of California ahead of
this cold front, with fresh to strong W to NW winds offshore Baja
California behind the front into Thu night. Seas offshore Baja
California will be at 8 to 12 ft during this period of higher
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Fresh to locally gap winds are occurring across the Gulf of
Papagayo due to high pressure building north of the area.
Moderate gap winds are also ongoing in the Gulf of Panama.
Elsewhere, light to gentle variable winds prevail over the
offshore waters of Central America and South America along with
seas of 3-5 ft due to a long-period south to southwest swell.
For the forecast, fresh to locally strong gap winds will prevail
across the Gulf of Papagayo and the coast of Nicaragua through
tonight. Moderate to fresh N to NE winds can be expected over
the Gulf of Panama as well into Wed. Gentle to moderate winds
and slight seas will prevail elsewhere through the period.
REMAINDER OF THE AREA...
Please see Special Features section above for details on a gale
warning well west of Baja California Norte Tue as well as
significant seas over the northern waters into mid-week.
The stationary front over the far NE waters has dissipated
overnight. A cold front extends from 30N125W to 24N140W. Ahead of
the front, fresh SW winds have developed N of 27N. Behind the
front, strong NW winds are occurring and seas have increased to
8 to 10 ft. Weak high pressure ridging is the main feature over
the area to the south. Moderate to locally fresh trade winds
mainly from 02N to 15N west of 118W are supporting combined seas
of 4-6 ft in that area. Generally slight seas are noted
For the forecast, the cold front will move east across the
northern and central waters through Wed as its southern part
weakens and dissipates. As the high pressure builds in behind
this front, trade winds will increase W of 125W between the
equator and 20N to fresh to strong for the latter half of the
week. Mainly gentle winds and slight seas will persist elsewhere
east of 110W into Thu.