296 AXPZ20 KNHC 171002 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Feb 17 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 0945 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough passes through the coastal sections of Panama near 09N78W to 08N82W and 04N99W. The ITCZ continues from 04N99W, to 01N110W, and 01N120W, to the Equator along 130W. Rainshowers are possible, within 60 nm to 90 nm to the north of the surface trough between 88W and 98W, within 150 nm to the north of the ITCZ between 99W and 103W, within 270 nm to the north of the ITCZ between 103W and 108W, and within 60 nm to the north of the ITCZ between 108W and 120W. Rainshowers are possible, within 240 nm to the south of the surface trough and the ITCZ, from 120W eastward. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A strong ridge extends SE across the discussion area, through 30N130W to 23N123W to 14N116W. The surface pressure gradient, between the ridge and lower surface pressure that covers the SW CONUS and Mexico, is supporting strong northwesterly winds across the offshore waters of Baja California and southward to 19N. Expect that the wind speeds will range from 25 to 30 knots, from 25N northward within 60 nm of the coast. The sea heights across this area range from 10 feet to 16 feet in NW swell. New large NW swell is entering the northern waters north of 28N, in order to produce sea heights that range will range from 8 feet to 15 feet. Long period NW swell of 14 to 18 seconds will continue to spread SE across these offshore waters through Monday. The sea heights will peak at 10 to 16 feet across all waters N of 20N on Sunday, before gradually subsiding to 8 to 12 feet on Monday. The combination of the strong winds and large NW swell will produce very rough and dangerous marine conditions across the open waters through Monday, and generate very large and shifting waves along the coasts. The wind speeds off Baja California will diminish gradually, to 20 knots on Monday, and to 15 knots from Tuesday to Wednesday night. Expect 10 knot wind speeds from Wednesday night until Friday night. The wind speeds will return to 15 knots on Friday night. The sea heights will range from 12 feet to 16 feet from Sunday into Monday, subsiding to 8 to 12 feet on Tuesday morning. The sea heights will fall to 8 feet or less by Wednesday night. A second surge of swell will start on Friday afternoon, with the sea heights ranging from 8 feet to 12 feet. The sea heights will return to 8 feet or less by Saturday night. Gulf of California: A strong surface low pressure center will move across the northern part of the Gulf of California tonight, bringing fresh to strong winds to the northern part of the Gulf of California. Expect fresh to strong winds in the northern part of the Gulf of California, also, from Thursday morning to Friday morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate northeast winds in the Gulf of Papagayo will diminish tonight, but resume again on Monday. The NE winds will be increasing to strong at night, and continuing through Wednesday morning. Light and variable winds are expected elsewhere through Thursday, except for the Gulf of Panama, where moderate northerly winds will dominate. REMAINDER OF THE AREA... A 1041 mb high pressure center, well to the north of the Hawaiian Islands near 41N146W, will persist across that region during the next several days, with an associated unusually strong ridge extending SE and into the tropics near 10N103W through Monday. This pattern currently is producing a tight pressure gradient across the entire area N of 08N and W of 110W, resulting in fresh to strong anticyclonic wind flow W OF 118W. The most current scatterometer data show that NE to E winds are in the 20 knots to 25 knots range, from 14N to 28N to the west of 125W. The sea heights range from 12 feet to 16 feet. New NW swell moving into the area has raised seas to 12 to 18 feet N of 25N between 125W and 135W. The sea heights elsewhere are in the 8 to 12 foot range. The strong ridge will strengthen slightly on Sunday, and generally remain in place in order to maintain the large area of strong NE to E winds across W and SW sections of the discussion area. The wind speeds and the sea heights will start to subside on Monday. The deep layered low pressure system, that has been affecting the Hawaiian islands during the past several days, is forecast to move northward. The strong ridge will be pushed to the east, and the ridge will weaken from 120W eastward. A weak cold front is forecast to enter the NE Pacific Ocean waters by Thursday morning. The peak sea heights with this next event are expected to reach only 11 to 12 feet in NW swell across NE parts of the area. $$ mt