000 AXPZ20 KNHC 160950 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Feb 16 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 0800 UTC. ...SPECIAL FEATURES... POPOCATEPETL VOLCANO at 19.0N 98.6W is in a state of unrest. Volcanic ash may be reaching the surface within 120 nm of the Pacific coast of Mexico between 99W and 105W. Mariners should exercise caution. If mariners encounter ash or floating volcanic debris, you are encouraged to report the observation to the National Weather Service by calling 305-229-4424. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough passes through the coastal sections of Panama near 07N78W, to 04N96W. The ITCZ continues from 04N96W to 02N116W, to the Equator along 120W, and to the Equator along 127W. Scattered moderate to isolated strong rainshowers are within 90 nm on either side of the surface trough and the ITCZ between 85W and 101W. A second ITCZ is along 01S82W 03S88W 02S92W 03S103W. Isolated moderate rainshowers are within 240 nm to the south of the ITCZ between 86W and 94W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A large and strong ridge is building into the region this morning from the NW. The ridge will begin to produce strong northerly winds across the offshore waters. Seas of 5 to 6 feet in NW swell prevail south of Punta Eugenia, while new NW swell arriving north of there is producing seas 6-9 feet. A cold front currently passes through 30N124W to 27N134W. A reinforcing and second front will sweep across Southern California and the same northern areas as the current cold front. A very strong and broad high pressure ridge will build from north of Hawaii southeastward across the region today and tomorrow. Fresh to strong northwest to north wind will develop tonight through Sat across the offshore waters of Baja California, and increase to 20-25 knots with possible small areas of gale force wind gusts on Saturday night. Large NW swell also will spread into the regional waters with this building ridge, raising seas to 8 to 11 feet west of Baja California on Saturday, and to 10 to 16 ft on Saturday night and Sunday. The combination of these strong winds and large NW swell will produce very rough and dangerous marine conditions across the open waters through the weekend, and produce very large and shifting waves along the coasts. South and east of Las Islas Revillagigedo, gentle to moderate NW to W winds will increase to moderate to fresh from Saturday through Sunday, with seas of 4 to 6 feet expected to build to 8 to 10 feet in this NW swell. A weak trough is expected to prevail near the coast of Manzanillo, allowing for little change in gentle winds east of there through Sunday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh northeast winds in the Gulf of Papagayo will diminish to the moderate range on Saturday afternoon, and change little through Sunday night. Gentle to moderate winds will remain elsewhere across the forecast waters through Tuesday, as a weak anticyclone sets up near 12N97W on Sunday. REMAINDER OF THE AREA... Strong high pressure centered well north of the Hawaiian Islands is building southeastward across the northern and central parts of the area, and into the tropical waters near 14N114W. This is producing a tight surface pressure gradient, between the remnants of a surface trough along 130W and the building ridge, resulting in fresh to strong NE to E winds from 09N TO 29N W OF 126W. New NW swell moving through this area is generating seas in the 9 to 13 feet range, except 12 to 15 feet N of 28N and W of 130W. This unusually strong ridge will strengthen slightly during the weekend, and remain generally in place, in order to maintain a large area of these strong NE to E winds across W and SW sections of the discussion area. The sea heights will subside slightly S of 22N during the weekend, to 9-11 feet, while the next surge of large NW swell moves across the N and NW waters, in order to produce sea heights of 10 to 14 feet this evening. The sea heights will be building to 12 to 16 feet by Saturday evening, before subsiding very slowly from Sunday into Monday. This pattern is being aided by a deep layered low pressure system across Hawaii. Abundant mid and upper-level moisture, in the form of overcast to broken mid and upper-level clouds, continues to stream northeastward in the strong jet stream originating south of Hawaii, associated with the upper level cyclonic circulation center. Elevated areas of rain and possible thundershowers created by this scenario will affect far W sections of the area through today. $$ mt