000 AXPZ20 KNHC 181005 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Feb 18 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 0845 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...Updated A surface trough passes through the coastal sections of Colombia near 06N77W, to 04N85W 05N98W and 01N110W. The ITCZ continues from 01N110W, to the Equator along 120W, and beyond the Equator along 140W. Scattered moderate to isolated strong rainshowers are within 210 nm to the north of the surface trough and ITCZ between 104W and 114W. Isolated moderate to locally strong rainshowers are within 75 nm to the north of the surface trough between 82W and 87W. Rainshowers are possible elsewhere within 240 nm to the north of the surface trough from 88W eastward, and within 450 nm to the north of the surface trough and the ITCZ between 96W and 125W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A strong and persistent ridge extends southeastward across the discussion area, from the NE Pacific Ocean, through 32N138W to 24N121W, to 14N113W. The tight surface pressure gradient, between the ridge and lower surface pressure that is covering the southwestern U.S.A. and Mexico, has been supporting strong northwest winds across the offshore waters for more than 24 hours. The wind speeds finally have begun to diminish to 15 to 25 knots, as the ridge is realigning itself in advance of an approaching cold front. The sea heights that are associated with these winds are in the range from 8 feet to 13 feet in NNW swell. The marine conditions remain rough and dangerous. A new cold front is sinking SSE across the offshore waters of Southern California, at this time. The front will sweep across far northern sections of Baja California through Monday night, and act to reinforce the NW wind flow. The surface pressure gradient will weaken slightly, leading to winds continuing to diminish to 15-20 knots, slowly, across most of the waters by Monday night, then become moderate to fresh on Tuesday and Wednesday. The seas also will subside gradually through Monday, as the current large NW swell moves SE of the area. Reinforcing NNW swell from the next approaching cold front will maintain the sea heights from 7 feet to 11 feet from Tuesday through Wednesday. Gulf of California: for the northern part of the Gulf of California...Low pressure and its associated cold front will move across the area tonight and on Monday morning. Expect fresh to strong SW to W winds ahead of the front tonight and on Monday morning. Expect fresh to strong NW winds behind the front from Monday morning into Monday afternoon. The wind speeds will become light and variable from Monday afternoon into Monday night. Moderate to fresh W to NW wind flow will develop on Monday night, and give way to fresh to strong NW winds on Tuesday morning and afternoon. Moderate to fresh NW winds will cover from Tuesday afternoon into Tuesday evening. Light to moderate variable winds will last from Tuesday evening into Wednesday afternoon. Light southerly winds on Wednesday night will become fresh to strong SW winds on Thursday morning, even with sea heights of 8 feet by Thursday afternoon...everything in advance of the next cold front. The fresh to strong SW winds will last until the cold front arrives to the area, on Friday morning/early afternoon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A gap event, with a pulse of NE winds from 20 to 25 knots, will start on Tuesday morning, and end by Tuesday afternoon. The wind speeds will pulse again, NE 20 to 25 knots, from Tuesday night until Wednesday morning. REMAINDER OF THE AREA... A strong 1042 mb high pressure center, well to the north- northeast of the Hawaiian Islands near 42N144W, will remain in this general location through Wed. The associated ridge axis extends southeastward through 32N138W to the tropics near 14N113W, which has forced the ITCZ southward to along the equator. The pressure difference between this ridge and broad low pressure lingering across the Hawaiian Islands area is resulting in a tight pressure gradient across most of the area N of about 08N and W of 110W. Northeast to east winds of 20 to 25 kt are generally west of a line from 30N140W TO 10N128W TO 09N128W TO 08.5N140W, where seas are in the range of 10 to 15 ft. This current overall synoptic pattern will change very little through the next couple of days as low pressure north of the Hawaiian Islands along 25N pulls northward and away from the islands. The area of strong northeast to east winds will persist, but over a gradually smaller section of the western side of the discussion area. The seas there will slowly subside to around the 10 to 12 ft through the next 48 hours as the large swell gradually propagates SE of the area. $$ mt