000 AXPZ20 KNHC 122155 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2154 UTC Tue Mar 12 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from Costa Rica near 08N83W to 05N90W. The intertropical convergence zone continues from 05N90W to beyond 04N140W. Scattered moderate to isolated strong thunderstorms are evident within 120 nm north of the ITCZ west of 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front reaches from 10007 mb low pressure over the Sonoran Desert near 30.5N112W to La Paz in Baja California Sur to 17N118W, where it becomes a weakening stationary front to 15N133W. Strong NW winds follow the front off the coast of Baja California Norte. Fresh westerly gap winds are probably developing in the northern Gulf of California near 30N, and may increase to 25 to 30 kt tonight. Large, long-period NW swell follows the front, and various recent altimeter passes indicate this swell is reaching at least 10 to 13 ft in the offshore waters north of Punta Eugenia, and 8 to 12 ft farther south to the Revillagigedo Islands. Hazardous surf conditions are possible along the coast of Baja California due the long period swell. The cold front moving through the southern Gulf of California and Los Cabos area will dissipate through early Wed. A reinforcing front will move into the waters off Baja California Norte early Wed, move south through the region before stalling and dissipating over the southern Gulf of California and Baja California Sur by early Thu. The NW swell currently off the coast of Baja California will continue to propagate southward, reaching near Cabo Corrientes by late Thu. High pressure building over the Great Basin will support at least fresh NW winds across the Gulf of California Thu. Farther south, gale force gap winds are possible in the Gulf of Tehuantepec by Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A modest ridge prevail across the SW North Atlantic and eastern Gulf of Mexico, and is producing a fairly tight pressure gradient over Central America and the Caribbean Sea. This pattern will continue to support fresh to strong northeast winds pulsing across the Gulf of Papagayo region through late week. Winds will be strongest during the overnight and early morning hours with the assistance of nocturnal drainage flow. Fresh to strong north to northeast gap winds will also pulse through the Gulf of Panama mainly at night through Tue night. Gentle to moderate winds with mixed swell will persist elsewhere through Sun. REMAINDER OF THE AREA... Strong high pressure ridging is building east-southeast across the waters in the wake of the previously described frontal boundary. Ship observations indicated earlier strong northerly winds north of 20N have diminished to moderate to fresh NE to E winds. The German research vessel Sonne near 14N125W is reporting NE winds to 25 kt along the dying frontal boundary. Long period NW swell persists over much of the region west of 120W, and various altimeter passes over the past several hours indicate wave heights to 12 ft. The swell will continue to propagate and cover much of the region west of 105W by late Thu. The swell will subside below 8 ft north of 15W, with 8 to 9 ft seas in a mix of NW swell and shorter period NE trade wind swell farther south into the tropics. Looking ahead, the swell will diminish below 8 ft almost everywhere through Sun, just as a new round of large, NW swell moves into the region south of 31N and east of 140W early Sun ahead of an approaching cold front along with strong SW winds. $$ Christensen