000 AXPZ20 KNHC 280406 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Jun 28 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 0000 UTC surface analysis and satellite imagery through 0350 UTC. ...SPECIAL FEATURE... Heavy rainfall over Central America from Costa Rica to Guatemala: Fresh SW flow is delivering increased moisture into the mountainous areas along the Pacific coast from Nicaragua to Guatemala. These winds are influenced by the interaction of a pair of tropical waves moving westward along the monsoon trough through the southwest Caribbean and south of Mexico. Locally heavy rainfall is possible into Fri. As broad low pressure moves NW toward southern Mexico, the heavy rainfall potential will spread into this region this weekend into early next week. Please refer to local weather advisories for more information. ...TROPICAL WAVES... The axis of a tropical wave is north of 05N along 94W, moving west around 10 kt. Scattered moderate isolated strong convection is from 06N to 15N between 83W and 99W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 12N87W to 11N92W to 11N110W to 10N126W. The ITCZ extends from 10N126W to 11N134W. For convection information, see the tropical waves section. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see Special Features section above for information on heavy rainfall potential this weekend over southern Mexico. A pair of weak surface troughs are noted W of Baja California, in the vicinity from 17N to 26N between 116W and 128W. These troughs are disrupting the typical pressure gradient between high pressure over the north Pacific and the lower pressure of the monsoon trough. Thus, winds are mainly gentle to locally moderate from the northwest across the Baja California offshore waters. Seas across the region are 3 to 5 ft, except 1 to 3 ft in the Gulf of California. For the forecast, broad low pressure will form over northern Central America Fri then move NW into southern Mexico this weekend, likely enhancing showers and thunderstorms offshore the Gulf of Tehuantepec and possibly bringing heavy rainfall. Otherwise, a weak pressure gradient over the area will generally maintain mostly gentle breezes and moderate combined seas across the Mexican offshore waters through the weekend. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See tropical wave and monsoon trough sections above for information on convection offshore Central America. Light to gentle winds persist across waters north of the monsoon trough, with mainly moderate SW winds to the south. Seas are 3 to 5 ft north of the monsoon trough and 5 to 7 ft to the south. For the forecast, broad low pressure over Central America will support moderate to fresh SW winds off southern Central America into Fri, along with moderate and showers and thunderstorms. The low pressure may strengthen some this weekend over northern Central America, enhancing convection and possibly leaving to heavy rainfall. Mainly gentle winds and moderate seas will persist elsewhere. ...REMAINDER OF THE AREA... Moderate to locally fresh winds are in the vicinity of a surface trough along 135W that resides between the monsoon trough and ITCZ. Elsewhere, a relatively weak pressure gradient across the waters north of the monsoon trough and ITCZ is leading to mainly gentle winds and moderate seas west of 110W. To the east, moderate to occasional fresh SW winds are noted S of the monsoon trough, in response to lower pressure over Central America ahead of a pair of tropical waves moving through the region. For the forecast, expect periods of fresh winds and 5 to 7 ft seas E of 110W south of the monsoon trough through the weekend. Little change is expected elsewhere. $$ Ramos