000 AXPZ20 KNHC 282142 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2142 UTC Wed Nov 28 2018 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N83W to 08N100W to the low pressure near 14N107W to 07N125W. The ITCZ continues from 07N125W to 06N140W. Scattered moderate convection is observed within 60 nm either side monsoon trough west of 115W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Numerous moderate to isolated strong thunderstorms are active within 120 nm to the northwest of a 1008 mb low pressure centered near 14N107W. Strong SW shear aloft related to a sharp upper trough north of the low is responsible for displacing the convection well to the northeast of the center. A scatterometer satellite pass from 16 UTC indicated fresh to strong SE winds in the area of thunderstorms. A concurrent altimeter pass just to the east of the area of strong winds showed seas to 8 ft. Wave heights are possibly reaching as high as 15 ft in the area of strong winds, with the assistance of long period SW and NW swell in the area. The low is expected to continue to move northeast into the waters off the coast of Mexico southwest of Manzanillo through Thu, before weakening and turning westward again Fri. The long period NW swell in excess of 8 ft pushed into the waters off Baja California last night, and will reach the Revillagigedo Islands this afternoon before continuing onto toward the area off Cabo Corrientes through Thu. Seas in excess of 12 ft in NW swell will dominate the waters off Baja California into Sat as a reinforcing group of NW swell moves into the area, associated with a cold front moving into the region Thu and Fri before dissipating Sat. Seas in excess of 8 ft will linger in the open waters off Mexico north of Acapulco through Sat. In the Gulf of California, strong west gap winds will follow the cold front into the northern Gulf late Thu into early Fri. In the Gulf of Tehuantepec, observations at Salina Cruz on the southern end of the isthmus were showing fresh to strong winds earlier today, but have recently diminished. Winds through the Gulf will similarly weaken through early Thu. Seas to 6 ft will persist in mixed swell into Thu then subside. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh NE winds will pulse across the Gulf each night through Sun night. Elsewhere, the monsoon trough will remain between 08N and 11N during the rest of the week, with gentle to moderate winds on either side of the trough, with 5 to 7 ft seas expected. REMAINDER OF THE AREA... Fresh trade winds were noted in an earlier scatterometer pass north of the monsoon trough to 20N and west 135W. Recent altimeters confirm a large area of 8 to 12 ft over most the region west of 120W. This is primarily due to long period NW swell, although a component of southerly swell was evident as well in wave model initializations. A cold front entering the northwest portion of the discussion area will move across the waters north of 20N through Sat, accompanied by by a new round of long period NW swell. Fresh westerly winds will follow the front north of 28N this evening through Thu. $$ Christensen