650 
AXPZ20 KNHC 212015
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sat Dec 21 2024

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 1800 UTC surface analysis and satellite imagery through
2000 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: The pressure gradient between 
high pressure over eastern Mexico and low pressure within the 
eastern north Pacific monsoon trough will support gale-force gap
winds in the Gulf of Tehuantepec through Sun night. Seas during 
the warning event will peak at 12 to 14 ft. The high pressure 
will shift east by early Mon, with the pressure gradient 
loosening. This will diminish winds below gale force early Mon. 
Please see the latest NWS High Seas and Offshore Waters Forecasts
issued by the National Hurricane Center at website:
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and 
www.nhc.noaa.gov/marine/offshores_eastpac.php for more 
details.

Significant NW swell: A complex and powerful low pressure north 
of the area will generate several rounds of large NW swell that 
will propagate into the area through early next week. This 
afternoon, seas greater than 12 ft cover the waters NW of a line
from 30N128W to 18N140W, with seas peaking in excess of 20 ft 
over the far NW waters. The rough to very rough seas will spread 
SE, covering the waters from west of Baja California near Punta 
Eugenia to 08N133W early Mon evening when a reinforcing set of NW
swell arrives with peak seas of 21 ft near 30N140W. NW swell 
will continue to be reinforced into the middle of next week. 
Please see the latest NWS High Seas Forecast issued by the 
National Hurricane Center at website:
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from 10N85W to 07N103W. The ITCZ 
extends from 07N103W to 08N115W to beyond 07N140W. Scattered 
moderate convection is noted from 05N to 09N E of 81W, and from 
04N to 07N between 92W and 102W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please read the Special Features Section for information on a 
Gale Warning in the Gulf of Tehuantepec, and on a significant NW
swell event that will impact the waters offshore Baja 
California.

Aside from the gale warning area, high pressure prevails over the
waters west of the Baja California peninsula. The pressure 
gradient between this area of high pressure and a trough over 
Mexico is supporting with gentle to moderate winds across much of
the forecast waters. Seas are in the 5 to 7 ft over the open 
waters off Mexico, and 1 to 3 ft over the Gulf of California. 

For the forecast, other than the aforementioned Gale Warning in 
the Tehuantepec region and significant NW swell, gentle to 
moderate mainly N winds will increase slightly this weekend as a 
NE Pacific high pressure ridge builds toward the region, and 
winds will pulse to moderate to fresh at times offshore Baja 
California.

...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, 
AND WITHIN 750 NM OF ECUADOR...

The pressure gradient between a surface ridge over the 
northwestern Caribbean Sea and the EPAC monsoon trough is 
supporting fresh to strong NE gap winds and seas of 5 to 7 ft in
the Gulf of Papagayo region. Light to gentle winds prevail 
elsewhere N of the monsoon trough, except well offshore Guatemala
where moderate to fresh winds are downwind from a Gulf of 
Tehuantepec gap wind event. South of the monsoon trough, gentle 
to moderate southerly winds and 4 to 6 ft seas in moderate S to 
SW swell prevail, mixed with NW swell from the Gulf of 
Tehuantepec gap wind event.

For the forecast, the pressure gradient between high pressure 
building toward the western Caribbean and the eastern north 
Pacific monsoon trough will support pulsing fresh to strong NE 
gap winds in the Papagayo region into early Wed. Gales in the 
Tehuantepec region will support northerly swell and rough seas 
well offshore Guatemala through the weekend. Elsewhere, winds 
will be moderate or weaker with moderate seas through early next 
week, pulsing to moderate to fresh in the Gulf of Panama at 
times. Seas may build mid-week in NW swell. 

...REMAINDER OF THE AREA...

Please read the Special Features section about very rough seas
expected over NW waters through the weekend and into early next
week.

A frontal boundary extends over the far NW waters from 30N132W to
28N140W. High pressure of 1025 mb is centered near 26N124W. The 
pressure gradient between these features is supporting moderate 
SW winds within 120 nm E of the cold front. Light to gentle winds
are in the vicinity of the high center. Gentle to moderate winds
prevail elsewhere N of 20N. The pressure gradient between the 
area of high pressure and lower pressure in the vicinity of the 
ITCZ is supporting moderate to fresh winds N of the ITCZ to 20N 
and W of 118W. S of the ITCZ, gentle to moderate trades prevail. 
Aside from the large swell discussed above, seas are mainly in 
the 6-9 ft range. 

For the forecast, other than the NW swell and very rough seas 
mentioned in the Special Features sections, little change in 
winds are forecast over the next several days while seas of 8 ft
or greater will cover most of the waters west of 110W by early 
next week, and then west of 100W by mid-week.

$$
AL