000 AXPZ20 KNHC 182157 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Feb 18 2018 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 2145 UTC. ...SPECIAL FEATURE... Gulf of California GALE WARNING: Strong to near gale force SW-W winds, with seas to near 8 ft, will develop across the waters from 29.5N to 31.5N on Sun evening ahead of a cold front that will pass E across the far northern gulf waters tonight through Mon night. Near gale force northerly winds are also forecast NW of the front on Mon and Mon night, except for a narrow band of minimal gale winds expected briefly on Mon night. Seas will build to 10 ft in the longer fetch waters N of 30N. The front will move E of the area on Tue, with marine conditions quickly improving thereafter. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends SW from the Pacific coast of Costa Rica at 09N85W to 07N100W where scatterometer winds indicate a transition to an ITCZ, which continues W to beyond 07.5N140W. A few TSTMS are flaring along the Pacific coast of Colombia within 30 nm either side of a line from 06.5N77W to 01N90W. Similar convection is observed within 30 nm of a line from 09N83W to 05N87W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A gentle variable breeze continues around a weak N to S orientated trough analyzed from 29N118W to 24N115W. A cold front will sweep quickly E across the discussion area N of 28N through tonight Mon eroding the trough. Strengthening high pressure in the wake of the front will result in a strong NW breeze spreading SE across the waters W of the Baja Norte on Mon into early Mon night, accompanied by NW swell building seas to 8 to 15 ft. The pressure gradient will relax on Tue with seas subsiding to less than 8 ft on Wed night. Gulf of Tehuantepec: High pressure across the Gulf of Mexico will support fresh to strong northerly surges through the Gulf of Tehuantepec tonight, with these strong northerly winds resuming on Thu evening. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Strong NE winds will continue to pulse through and downstream of the Gulf of Papagayo through this week, with seas building to 9 ft as downstream as 10N91W. Gulf of Panama: Fresh to locally strong nocturnal N winds are expected across the western Gulf of Panama tonight with these conditions extending as far S as 05N80W. Mostly fresh nocturnal drainage flow is then forecast through Fri night. Elsewhere, gentle to moderate offshore flow will prevail N of 09N while light to gentle SW winds are forecast S of 09N. REMAINDER OF THE AREA... A broad ridge covers the discussion waters N of the ITCZ and W of 120W, with 6 to 8 ft seas in mixing swell. Isolated moderate to strong convection has been flaring within 90 nm either side of a line from 20N118W to 14.5N128W. The pressure gradient will tighten tonight, with fresh to strong trades developing across the tropical waters W of 125W, while fresh to strong N winds will spread S across the northern waters in the wake of a cold front sweeping E across the Baja Peninsula. Conditions will improve briefly across the sub-tropics on Thu, the deteriorate again behind another cold front on Fri. $$ Nelson