000 AXPZ20 KNHC 140858 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Nov 14 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Excessive Rainfall Risk in Southern Central America: Persistent SW flow in the eastern Pacific region will continue to bring abundant tropical moisture across southern Central America. Latest model guidance indicates that the present moderate SW flow offshore Costa Rica and Panama is expected to increase toward the end of the week and into the upcoming weekend as a developing tropical disturbance meanders over the western Caribbean Sea. The abundant tropical moisture is forecast to provide a focus for potentially heavy rainfall to occur in Costa Rica and in western Panama. This information is provided by the Weather Prediction Center's International desk team. Please refer to your national weather agency for details. Large swell over the eastern Pacific: Large, long-period NW swell of 8 to 11 ft is impacting most of the region north of 10N west of 115W. A reinforcing group of NW swell is starting to move into the region from the north-central Pacific, following a cold front that will move eastward across the waters through late Fri. The reinforced NW swell will bring wave heights of 12 to 14 ft to the region north of 20N and west of 115W through late Fri. Wave heights will subside north of 25N by Sat, but 12 to 13 ft seas will persist into Sun from 12N to 22N west of 130W, where the NW swell will mix with shorter-period NE waves associated with fresh to strong NE trade wind flow. Combined seas in excess of 8 ft will persist mainly north of 05N and west of 105W into Mon. Gulf of Tehuantepec Gale Warning: A recent scatterometer satellite pass indicated strong N gap winds starting over the northern Gulf of Tehuantepec. These winds are associated with high pressure surging southward along the eastern slopes of the Sierra Madre Mountains in Mexico behind a cold front moving across the Gulf of Mexico. The gap winds will reach minimal gale force later this morning, supporting rough seas downstream by afternoon within 60 nm of the coast, and very rough seas by this evening with the plume of seas in excess of 8 ft reaching as far south as 10N by early Fri. Winds will drop below gale force early Fri morning, with overall winds and seas will diminish Fri and Sat as the high pressure weakens and shifts eastward. Gentle breezes and slight to moderate seas will prevail by late Sun. For more details, please read 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 the Costa Rica/Nicaragua border near 11N86W to 15N95W to 1011 mb low pressure near 13N108W, to a 1011 mb low pressure near 10N117W, to 1011 mb low pressure near 09N127W, to 07N140W. Scattered moderate convection is active from 12N to 15N between 91W and 93W, from 13N to 16N between 100W and 110W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure is building over the eastern Pacific behind a cold front approaching Baja California from the west. This pattern is supporting fresh NW winds over the Gulf of California this morning, reaching as far south as Tres Marias. Large NW swell of 8 to 11 ft is also impacting the waters off Baja California close to the coast near Punta Eugenia, but beyond 120 nm off Cabo San Lucas. Farther south, a gap wind gale event is starting across the Gulf of Tehuantepec, as described in the Special Features section. Gentle to moderate breezes persist elsewhere, with 4 to 6 ft seas primarily in NW swell in open waters, with 3 to 5 ft in the Gulf of California. For the forecast, please see the Special Features section for information about the Gulf of Tehuantepec gale warning. Elsewhere, the large NW swell event moving through the waters off Baja California Norte will reach Clarion Island later today. A cold front will move into Baja California Norte by late today, then weaken and dissipate by late Fri. Expect fresh SW to W winds in the northern Gulf of California ahead of the front late tonight, becoming fresh NW winds Fri as the front moves through the region. Looking ahead, another round of reinforcing NW swell will follow the front, reaching the waters off Cabo San Lazaro on Fri, and Socorro Island by late Sat, and well offshore of Cabo Corrientes by late Sun. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please refer to the Special Features section for details on an excessive rainfall risk in southern Central America. Gentle to moderate S to SW winds are noted off southern Central America per recent scatterometer data, with gentle breezes farther south. Seas are in the 3 to 5 ft. For the forecast, gentle to moderate SW winds will increase to moderate to fresh across the coastal waters from western Panama to Nicaragua Fri and Sat, supported by a developing tropical disturbance over the northwest Caribbean. Farther north, large northerly swell related to a gap wind event in the Gulf of Tehuantepec will impact the outer offshore waters of Guatemala and El Salvador tonight through Sat. Elsewhere, gentle to moderate winds and moderate seas in SW swell are expected. ...REMAINDER OF THE AREA... Please refer to the Special Features sections for details about large swell over the eastern Pacific. A cold front is moving across the far NW corner of the forecast region, and extends from 30N127W to 28N140W. Moderate to locally fresh northerly winds and a new swell event follow the front. Building high pressure in the wake of the front is supporting a broad area of moderate to fresh NE to E winds across the region north of 10N and mainly west of 125W. These winds are accompanied by large NW swell described above in the Special Features section. In addition, an earlier altimeter satellite pass indicated seas of 8 to 10 ft across the waters 06N to 10N between 110W and 115W associated with mix of NW swell and wind waves due to fresh NE flow along the monsoon trough, and related to a low pressure area that is pulsing along the monsoon trough. Moderate winds and seas are noted elsewhere. Scattered showers and isolated thunderstorms are near the low pressure centers located along the monsoon trough. For the forecast, the above mentioned cold front will move across the waters north of 20N through Fri while weakening. Long-period NW swell behind the front will reinforce the existing field of swell across the waters ultimately extending as far as south of 05N and west of 105W through Sun. Wave heights to 14 ft can be expected north of 20N through at least Fri night. Fresh to strong trade winds will also cover the basin N of 10N and west of 110W as high pressure builds in the wake of the front. $$ Christensen