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AXPZ20 KNHC 180356

TWDEP 



Tropical Weather Discussion

NWS National Hurricane Center Miami FL

0405 UTC Sat Jan 18 2025



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 0000 UTC surface analysis and satellite imagery through

0300 UTC.



...SPECIAL FEATURE...



Gulf of Tehuantepec Gale Warning: Strong high pressure will build

over northeastern Mexico and the western Gulf of Mexico late Sun

following the passage of cold front across the region. This

pattern will support gap winds pulsing to gale force Sun night

into Mon, and subsequently rough to very rough seas downstream 

of the Gulf of Tehuantepec through Mon evening. These winds and

seas will diminish through early Tue as the high pressure weakens

and shifts eastward ahead of the next front moving into the

northwest Gulf of Mexico. An even stronger area of high pressure

will build over northeast Mexico and the western Gulf, supporting

strong gales or even storm force winds across the Gulf of

Tehuantepec through mid week, accompanied by a broad area of

rough to very rough seas downstream.



Climatologically, the first gale-force event of the season occurs

in mid-October, with the final gale-force event occurring in 

late March or early April. Occasionally, gale-force events may 

occur as early as September, and as late as May. The monthly 

distribution of Tehuantepec events shows that the largest number 

of gale force events occurs in December. Storm-force events occur

most often in January. 



Please refer to the latest NWS High Seas Forecast issued by the 

National Hurricane Center at the website: 

https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml, for more details.



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



The monsoon trough extends from 09N79W to 01N95W. The ITCZ

extends from 01N95W to 07N120W, and from 06N126W to 06N140W.

Scattered moderate convection is active from 09N to 10N between

111W and 117W, and from 06N to 08N between 130W and 133W.



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



A ridge extends from 1027 mb high pressure near 33N134W to near

Cabo Corrientes. This pattern is supporting moderate NW to N

winds and 4 to 6 ft seas over open waters north of 18N, and

gentle breezes with 3 to 5 ft seas elsewhere. 



For the forecast, the main issue will be successive cold fronts 

moving through the western Gulf of Mexico and southern Mexico, 

supporting pulses of gale- force gap winds across the Gulf of 

Tehuantepec Sun night, with strong gales possible Tue night 

through mid week. This pattern will also support rough to very 

rough seas downstream of the Gulf of Tehuantepec off eastern 

Oaxaca and Chiapas. The situation will be monitored over the next

few days, and a Storm Warning may be required. Elsewhere, a 

ridge will continue to dominate the offshore waters of Baja 

California this weekend producing mainly gentle to moderate winds

with moderate seas. Long period NW swell will reach the waters 

north of Punta Eugenia early Mon morning building seas to 8 ft 

there. In the Gulf of California, expect fresh to locally strong 

NW winds Mon night through early Wed as strong high pressure 

settles over the Great Basin of the United States. Gentle to 

moderate winds and slight to moderate seas will persist elsewhere

through at least Sun.



...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, 

AND WITHIN 750 NM OF ECUADOR...



Fresh E winds are ongoing at Liberia, Costa Rica. This is a good

indication fresh to strong gap winds persist across the nearby

Gulf of Papagayo. Gentle breezes are noted elsewhere over

offshore waters from Ecuador to Guatemala. Seas are 2 to 4 ft,

except to 6 ft over the Gulf of Papagayo.



For the forecast, fresh to strong winds and moderate seas will 

prevail in the Papagayo region over the next several days. The 

next gap wind event is forecast in the Papagayo area by Wed night

as a strong high pressure builds north of area. Light to gentle 

winds and slight to moderate seas will prevail elsewhere. Seas 

generated by strong gale force winds in the Tehuantepec area will

propagate across the offshore waters of Guatemala and El 

Salvador Mon and Mon night, then again Wed and Wed night.



...REMAINDER OF THE AREA...



A 1027 mb high pressure is centered north of area near 33N134W. 

Its associated ridge dominates most of the waters north of the 

ITCZ and west of 110W. A surface trough is analyzed along the

ITCZ between 120W and 125W. This pattern is supporting fresh to

strong NE winds and 8 to 10 ft from 08N to 18N west of 125W.

Gentle to moderate breezes and moderate seas persist elsewhere. A

few showers and thunderstorms are noted along the surface trough. 



For the forecast, the surface trough along the ITCZ between 120W

and 125W will move westward over the next couple of days. The 

area of fresh to strong winds and rough seas will move in tandem 

with this trough due to the pressure gradient between the trough 

and high pressure to the north. In addition, the pressure 

gradient between the high pressure and another surface trough 

approaching from the west will bring fresh to strong E to SE 

winds and building seas of 8 to 11 ft across the waters north of 

20N and west of 135W by Sun. 



$$

Christensen