000 AXPZ20 KNHC 272121 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Jun 27 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 2030 UTC. ...SPECIAL FEATURE... Heavy rainfall over Central America from Costa Rica to Guatemala: Fresh to locally strong 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 southern Central America. 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. Please refer to local weather advisories for more information. ...TROPICAL WAVES... The axis of a tropical wave is north of 04N along 92W through Guatemala, moving west around 10 kt. A surge of fresh to strong SW winds is supporting scattered moderate to strong convection from 05N to 10N between 87W and 97W. The axis of a tropical wave is along 101W from 05N to 15N. It is moving west at around 5 kt. Convection previously associated with this wave has diminished. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 09N88W to 13N105W to 11N115W to 11N133W to 11N134W to 09N135W. The ITCZ extends from 09N135W to beyond 08N140W. Scattered moderate convection is noted E of 87W. Scattered moderate convection has also developed from 08N to 12N between 110W and 115W. ...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 18N to 24N between 117W 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 across the basin. Some offshore NW flow is leading to moderate to locally fresh winds offshore Cabo San Lucas. Seas through the basin are 3 to 5 ft, except 1 to 3 ft in the Gulf of Tehuantepec. 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 noted within 120 nm north of a low pressure 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. $$ Konarik