000 AXPZ20 KNHC 040918 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0918 UTC Tue Jun 4 2019 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across Central America and southern Mexico to 16N96W to 10N100W to 07N110W to 11N120W. The ITCZ continues from 11N120W to beyond 07N140W. Scattered moderate convection is occurring from 03N to 07N between 94W and 99W and within 120 nm south of the ITCZ west of 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between high pressure west of the area and a low pressure trough near Baja California is maintaining NW flow across much of the region. A 04Z scatterometer pass over the Baja California offshore waters west of 113W showed gentle NW breezes across the area. Earlier ship observations closer to the coast indicated moderate to locally fresh NW winds were occurring between Punta Eugenia and Cabo San Lucas. Recent altimeter data off Baja California Sur showed 4-6 ft seas, likely in SW swell mixed with NW wind waves. Scattered moderate convection is noted within 60 nm of the coast of Guerrero. Weak low pressure will persist off the coast of southern Mexico through Wed before dissipating. The ridge will weaken slightly through mid week as gentle to moderate winds persist across much of the area with seas less than 8 ft. Northerly swell will enter the waters off Baja California Norte by Fri with seas building to 8-9 ft west of Guadalupe Island Fri night into Sat. Scattered showers and thunderstorms over portions of southeastern Mexico are associated with a broad area of low pressure over the Bay of Campeche. This system will likely continue to produce heavy rainfall over southern Mexico during the next couple of days as low pressure slowly tracks northwest toward the Mexican coast. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure pattern prevails across the region as overnight scatterometer data showed light and variable winds off the coast of Central America. Scattered moderate convection is noted from 06N to 08N between 77W and 81W. A 02Z altimeter pass showed a small region of 8 ft seas near 11N91W, but these wave heights are expected to subside later today as SW swell begins decaying. Farther south, altimeter data near the Galapagos Islands revealed 7-9 ft seas as SW swell dominates the southern waters. Seas will build to 8 ft off the coast of southern Colombia Tue night and Wed as the swell propagates northward toward the Gulf of Panama. Wave heights will briefly subside before a reinforcing set of SW swell arrives over the southern waters on Thu, which will maintain 8 ft seas through Sat. REMAINDER OF THE AREA... A ridge extends southeastward from 1026 mb high pressure near 35N138W to the Revillagigedo Islands. Moderate trade winds prevail between the ridge and the ITCZ per 05Z-06Z scatterometer data over the waters west of 125W. Little change is expected through mid week as a weak high pressure ridge persists over the northern waters. By Fri, stronger high pressure will build north of the area. The enhanced pressure gradient will result in fresh N to NE winds over the waters north of 26N with combined seas building to 8-10 ft, highest between 120W and 130W. Farther south, recent altimeter data indicated 8-9 ft seas extend as far north as 04N between the Galapagos Islands and 100W. Southern hemisphere swell will dominate the forecast waters east of 120W this week as reinforcing sets of S to SW swell move northward into the southern waters Thu and Fri. Seas will generally remain 8 ft over the waters south of the Equator through Sat. $$ Reinhart