000 AXPZ20 KNHC 040241 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Jun 04 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 0000 UTC surface analysis and satellite imagery through 0215 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends across Central America and southern Mexico and enters the Pacific at 16N95W. It continues from there to 10N102W to 07N108W and to 11.5N120W, where latest scatterometer data indicated that it transitions to the ITCZ to 07N131W and to beyond 06N140W. Scattered moderate to strong convection is seen north of 13N to the coast of Guatemala between 90W and 92W. Scattered moderate convection is within 60 nm of the ITCZ west of 136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Ship observations and a scatterometer satellite pass from Mon afternoon indicated gentle to moderate NW winds for the most part off Baja California along with light to gentle breezes over most of the Gulf of California. The mild conditions are ongoing between high pressure west of the are and a trough that extends from California southeastward to across the northern Gulf of California. An Ascat pass from 1702 UTC today nicely revealed locally higher fresh to strong northwest winds south of Cabo San Lucas. In addition, early on Mon afternoon ship with call ID "A8SI4" located at 22N110W reported northwest winds of 25 kt. The earlier fresh south to southwest winds over the northern Gulf of California near 30N have diminished to gentle to moderate speeds this afternoon. Farther south, a weak pressure pattern is maintaining light to gentle winds. The earlier observed overnight drainage related thunderstorms that were active off the Mexican coast off from western Oaxaca through the coast of Guerrero are weakening. Long-period southwest swell continues across the open waters supporting 4 to 6 ft seas. The ridge will weaken through Tue as a weak trough moves across Baja California Norte and the northern Gulf of California, allowing moderate to fresh southerly winds over the far northern Gulf of California late Wed. The trough is related to a deep layer cut off low pressure area migrating across the southwestern United States. Farther south, weak low pressure will remain nearly stationary off the coast of southern Mexico through late Tue along the monsoon trough. Northerly swell will reach the waters off Baja California Norte by Fri. Scattered showers and thunderstorms over much of southeastern and southern Mexico and the western section of Guatemala are in association with a broad area of low pressure over the Bay of Campeche. This system will likely continue to produce heavy rainfall over southern Mexico and over some areas of Guatemala during the next couple of days as unstable atmospheric conditions and available daytime heating, when skies are absent of dense cloud cover, combine to provide further activate this activity. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle west to southwest winds persist over the Central American offshore waters south of the monsoon trough with seas generally ranging from 4-7 ft in SW swell. Long-period southwest swell over the southern waters between Ecuador and the Galapagos Islands is likely producing seas to 8 ft. Seas will briefly subside Tue night through Wed before another long-period southwest swell event brings 8 ft seas by late week. Scattered moderate convection is well to the southwest of Central America within 30 nm of a line from 05N92W to 03N98W. REMAINDER OF THE AREA... A ridge extends southeastward from a 1027 mb high center located well to the northwest of the area near 36N139W to the Revillagigedo Islands. The earlier observed seas to 8 ft attributed to northerly swell north of 29N between 128W and 132W have subsided to below 8 ft. Moderate to locally fresh northeast trade winds continue between the ridge and the ITCZ. Trade winds will diminish slightly over the next couple days as the ridge weakens over the high seas. By Fri, stronger high pressure will build into the area from the NW. The resulting pressure gradient will result in fresh north to northeast winds over the waters north of 26N with combined seas building to 8-10 ft. The highest of the these seas are expected in the far NE waters. Farther south, altimeter data from this afternoon again indicated wave heights peaking to 8 ft south of the Equator generally west of 100W. Residual swell will decay from west to east through Tue. Another long-period southwest swell event will propagate through the far southern waters from late Wed through Fri, with seas once again peaking to 8 ft south of the Equator. $$ Aguirre