000 AXPZ20 KNHC 181604 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Jun 18 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...SPECIAL FEATURES... Central America and southern Mexico Heavy Rainfall Event: Potential Tropical Cyclone One (PTC One) over the southwestern Gulf of Mexico as of 15Z continues to sustain convergent monsoonal winds and draw abundant moisture from the Pacific Ocean into the coastal terrain of Central America and southern Mexico. This pattern will linger at least through late week, enhancing heavy rainfall and strong thunderstorms. This can cause life- threatening conditions that include flooding and mudslides. Numerous heavy showers and thunderstorms have persisted near the coasts of Oaxaca and Chiapas States in Mexican overnight. Areas expecting the heaviest rainfall through Sat continue to be the northwest portion of Nicaragua, eastern and central Honduras, El Salvador, coastal sections of Guatemala and the Mexican state of Chiapas. Additionally, dangerous surf conditions will impact these coastal areas through the next few days. Please refer to your local meteorological and emergency management office bulletins for more detailed information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends southwestward from the offshore waters of the state of Guerrero near 15N104W southwestward to 09N120W to 06N130W to 05N136W, where it transitions to the ITCZ and continues westward to beyond 06N140W. Scattered moderate to strong convection is within 120 nm south of the trough between 121W and 124W. Scattered moderate convection is within 60 nm south of the trough between 119W and 124W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the Special Features section above for details on a heavy rainfall event. Refer to the ITCZ/Monsoon Trough section for convection in the region. Potential Tropical Cyclone One mentioned in the Special Features section is sustaining fresh to strong with locally near-gale SW to W winds and 8 to 11 ft seas over the offshore waters of Oaxaca and Chiapas States in southern Mexico. Meanwhile, moderate to fresh NW winds and seas of 7 to 9 ft in residual NW swell linger west of Baja California Norte. Gentle to moderate W to NW winds with 5 to 7 ft seas exist near Baja California Sur and central Mexico. Gentle to moderate southerly winds along with seas of 1 to 3 ft are present over the Gulf of California. For the forecast, fresh to strong SW to W winds, rough to very rough seas, and numerous heavy showers and strong thunderstorms will impact the offshore waters of southern Mexico through Fri morning, primarily off Chiapas, Oaxaca and southeastern Guerrero States. Dangerous surf is also anticipated along the coastal areas of this region until Fri evening. Farther north, fresh NW winds and rough seas will persist off Baja California Norte until late this morning, primarily beyond 120 nm offshore. Residual NW swell in these waters mainly north of Cabo San Lazaro will gradually subside through tonight. From Wed evening through Fri morning, fresh to strong NW winds and rough seas should develop near Baja California Sur, including waters near Cabo San Lucas as pressure gradient increases. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Refer to the Special Features section above for details on a heavy rainfall event. Potential Tropical Cyclone One mentioned in the Special Features section is sustaining moderate to fresh with locally strong SW to W winds and 7 to 9 ft seas across the offshore waters of Guatemala and El Salvador. For the rest of the Central America, and Colombia offshore waters, gentle to moderate WSW to W winds and seas of 4 to 6 ft exist. These convergent monsoonal winds are triggering scattered showers and isolated thunderstorms near the coast of Guatemala, El Salvador, Panama and Colombia. Near the Galapagos Islands and off Ecuador, gentle to moderate southerly winds and seas at 6 to 8 ft in moderate southerly swell prevail. For the forecast, fresh to strong SW to W winds, rough to very rough seas and numerous heavy showers and strong thunderstorms will persist across the offshore waters of northern Central America through Fri. Dangerous surf is also anticipated along the coastal areas of this region until Fri evening. Farther south, rough seas in moderate to large southerly swell will continue near the Galapagos Islands and offshore of Ecuador through Wed. ...REMAINDER OF THE AREA... Refer to the ITCZ/Monsoon Trough section for convection in the region. A broad surface ridge extends southeastward from a 1025 mb high that is northeast of Hawaii to west of Baja California Sur near 20N119W. The associated gradient is supporting moderate to fresh NNW to NE winds and seas of 6 to 8 ft in northerly long-period swell north of 18N and west of 120W. Gentle to moderate NE winds and 5 to 7 ft seas in generally moderate northerly swell are evident farther southwest from 08N to 18N and west of 127W. Light to gentle winds and seas of 4 to 6 ft due to mixed moderate swell are over the waters near the ITCZ and monsoonal trough west of 118W. South of the monsoon trough from 07N to 14N and east of 118W, fresh to locally strong SW to W winds and 7 to 9 ft seas are noted. For the remainder of the region, gentle to moderate southerly winds and seas at 6 to 8 ft in moderate to large southerly swell prevail. For the forecast, the high pressure and related ridge will gradually weaken starting this afternoon, which should allow winds and seas north of 18N and west of 120W to subside through Thu morning. South of the monsoon trough from 07N to 12N and east of 118W, fresh to strong SW to W winds will become more widespread with seas building to between 8 and 10 ft by Wed. Scattered moderate convection in this same general area is anticipated to persist through at least Thu. Seas of 6 to 8 ft will shift west of the Galapagos Islands by Wed. $$ Aguirre