000 AXPZ20 KNHC 120952 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 952 UTC Sat Jan 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning...High pressure building north of the region behind a cold front moving across the Gulf of Mexico today and Sun will support pulses of strong to near winds through the Gulf of Tehuantepec by late today. These winds will reach minimal gale force by late Sun, and persist through early next week. Strong gap winds will continue to pulse through mid week then gradually diminish as the high pressure weakens and shifts east of the area. Seas will build to as high as 14 in the area of gale force winds, with NE swell in excess of 8 ft reaching as far as 600 nm W-SW downstream, mixing with longer period NW and SW swell through early next week. For more information, see the East Pacific High Seas Forecast under WMO/AWIPS headers FZNT02 KNHC/HSFAT2. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from the coast of Colombia near 04N77W to 05.5N100W. The ITCZ continues from 05.5N110W to beyond 05N140W. No significant showers or thunderstorms are observed. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front approaching the area from the west will weaken as it reaches the northern coast of Baja California Norte and Guadalupe Island later this morning. The front will lose definition as it continues east through Baja California and the Gulf of California through tonight and become diffuse by early Sun. Long period NW swell of 8 to 11 ft will accompany the front and this will move into the offshore waters of Baja California and the western Revillagigedo Islands through late Sun. The swell will largely subside below 8 ft from north to south through early Mon, just ahead of another dissipating cold front approaching from the west delivering a new round of large NW swell. The reinforcing push of NW swell will move over most of the open offshore waters of Baja California and the Revillagigedo Islands, and reach as far south as off the coast of Cabo Corrientes through mid week. Gulf of California: Light to gentle winds and slight seas will persist through mid week, except for brief periods of 10 to 15 kt winds over the northern Gulf, influenced by the slow pass of weakening cold fronts tonight and again late Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh NE to E winds will prevail across the Gulf region, and become fresh to strong across and downstream of the Gulf of Papagayo each night through the weekend primarily from the nocturnal drainage flow. Gulf of Panama: Moderate to fresh northerly winds downstream to near 05N with seas to 6 ft will continue through the weekend. There were indications yesterday of possible volcanic ash reaching the Pacific offshore waters of Nicaragua, originating from the San Cristobal volcano. Further analysis showed this was actually mostly steam and other gases. The volcanic ash advisory issued yesterday has been cancelled accordingly, and the original plume has dissipated since yesterday. Mariners transiting off the northwest coast of Nicaragua with respiratory sensitivities should use caution through this morning. REMAINDER OF THE AREA... A cold front extending from 30N120W to 21N135W to 22N140W will move east of the area today and tonight will dissipating. Recent altimeter data and ship observations indicate seas of 10 to 15 ft in NW swell following the front over the waters north of 22N. This swell follows previous swell in excess of 8 ft lingering south of 18N. High pressure will build in the wake of the front and support development of fresh to strong trade winds farther south, from 07N to 12N west of 135W tonight through late Sun. Another cold front will enter the discussion area late today, moving into the waters north of 25N. Strong SW flow is expected at least north of 28N ahead of the front late today and tonight as the front moves between 140W and 130W. While the current large swell north of 25N will have subsided by tonight to less than 12 ft, this new cold front will be accompanied by reinforcing swell of 12 to 15 ft across the waters north of 25N Sun into Mon. Looking ahead, yet another cold front is expected to follow the first two, entering the area Mon through mid week, with continued pulses of strong west winds and swell in excess of 12 ft. $$ Christensen