000 AXPZ20 KNHC 280930 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0920 UTC. ...SPECIAL FEATURE... Heavy rainfall for Central America and eastern Mexico: Moderate to fresh SW flow is delivering increased moisture into the mountainous areas along the Pacific coast from Costa Rica to Guatemala. Two tropical waves, one moving across Honduras, Nicaragua, and Costa Rica, and a second wave moving across Guatemala, El Salvador and Chiapas, Mexico are modulating the scattered heavy showers and thunderstorms over these regions. Numerous moderate to strong covection is affecting southern Honduras and Guatemala, and its offshore waters where recent scatterometer data show near gale force winds. Rough seas are likely over these offshore regions along with low visibilities. As broad low pressure moves NW toward southern Mexico, the heavy rainfall will spread into this region over the weekend and into Mon. Please refer to local weather advisories for more information. ...TROPICAL WAVES... A tropical wave extends from 06N to 16N with axis near 95W, moving west around 10 kt. Scattered moderate isolated strong convection is from 06N to 15N between 83W and 99W. Numerous moderate to strong convection is from 11N to 15N between 87W and 94W. Scattered moderate convection is from 05N to 09N between 88W and 95W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 12N87W to 11N90W to 11N100W to a 1011 mb low near 11N108W to 09N125W. The ITCZ extends from 09N125W to 10N134W. Aside from the convection associated with the tropical wave mentioned above, scattered moderate convection is over the Costa Rica offshore waters from 07N to 11N between 82W and 87W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see Special Features section above for information on heavy rainfall potential this weekend over southern Mexico. Recent scatterometer data show the continuation of gentle to moderate NW winds along the Baja California offshore waters, except N of Punta Eugenia where a tighter pressure gradient supports moderate to fresh winds and 5-6 ft seas. Light to gentle winds are across the S and SW Mexican offshore waters along with 3-4 ft seas. In the Gulf of California, winds are gentle to locally moderate from the south and seas are 1-3 ft. For the forecast, broad low pressure over northern Central America is forecast to move NW into southern Mexico this weekend, enhancing heavy showers and thunderstorms offshore the Gulf of Tehuantepec. Otherwise, a weak pressure gradient over the area will generally maintain mostly gentle breezes and moderate combined seas across the Mexican offshore waters through Tue night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See tropical waves and monsoon trough sections above for information on convection offshore Central America. Scatterometer data showed fresh to near gale force SW winds N of 10N and in the region of heavy showers and tstms off Guatemala and El Salvador. Seas in that region are 6 to 8 ft. South of the monsoon trough or S of 10N, between 81W and 92W, winds are moderate to fresh from the SW and seas are 5-7 ft. Across the offshore zones between Ecuador and The Galapagos Islands, winds are gentle to moderate from the south and seas are 3 to 5 ft. For the forecast, broad low pressure over northern Central America will support moderate to fresh SW winds across the offshore waters of Costa Rica and Nicaragua through tonight. Afterward, gentle to moderate S to SW winds are forecast through Tue night along with moderate seas. Scatttered heavy showers and tstms are forecast to continue across the Central America offshore waters through Sun. ...REMAINDER OF THE AREA... Surface ridging extends SE from a 1026 mb high pressure center near 37N139W. The ridge covers the subtropical waters W of 123W where seas are in the 4-5 ft range. South of the ridge, a surface trough breaks the ITCZ, extending from 13N135W to 08N138W. Recent scatterometer data show moderate to fresh NE winds in the vicinity of the trough between 129W and 140W. Seas are 5-7 ft in this area of enhanced winds due to a tighter pressure gradient. N of 25N between 120W and 130W, a tighter pressure gradient between lower pressure over Baja California and the ridge supports moderate to fresh N to NW winds and 5-7 ft seas in NW swell. East of 110W, moderate to fresh SW winds and seas to 7 ft prevail S of the monsoon trough, in response to lower pressure over Central America and 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