000 AXPZ20 KNHC 092142 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2140 UTC Tue Apr 9 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Gulf of California Gale Warning: A cold front associated with a developing low pressure system over the Great Plains will move S across the northern and central Gulf of California tonight and Wed. Strong to gale force northerly winds will quickly develop over the far northern portions of the Gulf behind the front and spread southward to the Tiburon Basin by around sunrise before diminishing below gale force. Seas will quickly build to 6-10 ft during this period. The front will then sweep S through the central portions of the Gulf on Wed before dissipating across the southern portion Wed evening. A widespread area of 20-30 kt NW winds will spread S behind the front on Wed with seas building to 5-8 ft. Winds and seas will diminish from N to S Wed night through Thu. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N83W to 06N90W to 1011 mb low pressure near 06N101W. The ITCZ continues from 06N101W to 04N110W to 06N120W to beyond 04N140W. Scattered moderate and isolated strong convection is noted within 120 nm of the trough between 83W and 88W. Scattered moderate convection is occurring from 10N to 12N between 117W and 119W and within 90 nm north of the ITCZ between 134W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad high pressure ridge extends SE across the Baja California offshore waters to the Revillagigedo Islands. Recent scatterometer data showed fresh to strong northerly winds over the offshore waters north of 28N west of Baja California. Winds will strengthen to near gale force north of Punta Eugenia tonight into Wed with seas building to 10-16 ft as strong high pressure NW of the region expands into the area. Strong NW winds are expected as far south as Cabo San Lazaro through Wed with seas generally 9-14 ft. Winds will remain fresh north of Cabo San Lazaro through Fri night before diminishing this weekend as the pressure gradient relaxes. Large, long period NW swell has moved beyond the Revillagigedo Islands to as far east as 105W. The swell will continue producing dangerous surf conditions along the coast of Baja California through Wed. The swell will continue spreading across the southern offshore waters to as far south as Puerto Angel through Wed, causing seas to build to 6-8 ft. Gulf of California: Please see the Special Features section above for information about the gale warning in effect for the northern Gulf of California on Tue night. Gulf of Tehuantepec: A narrow plume of fresh northerly gap winds was evident in earlier scatterometer data across the Gulf of Tehuantepec. Gap winds will briefly pulse to strong speeds later tonight with seas building to 7-8 ft. Winds will diminish to gentle to moderate speeds Wed and persist through much of the weekend. Looking ahead, the next potential Gulf of Tehuantepec gap wind event could begin late Sun night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Light to moderate winds will prevail in the Gulf of Papagayo region through Sun night. Seas in the 4-6 ft range will gradually subside to 3-5 ft by Fri night and persist through the weekend. Gulf of Panama: Light to gentle breezes will prevail across the Gulf of Panama region this week. Seas will generally remain in the 4-7 ft range through Fri night in SW swell, then subside to 3-5 ft over the weekend. Elsewhere, light to gentle winds will persist through the week. Wave heights between Ecuador and the Galapagos Islands will generally remain 5-7 ft through Fri as cross equatorial, long period SW swell moves across the region. Further offshore, seas will peak around 8 ft Wed night into Thu SW of the Galapagos Islands. REMAINDER OF THE AREA... High pressure is building across the northern waters in the wake of a weakening cold front. Earlier scatterometer data revealed fresh to strong winds across the high seas roughly north of 20N and west of 125W. A recent altimeter pass in this region showed seas generally ranging from 9-12 ft. South of the ridge, fresh trade winds prevail between 10N and 20N west of 130W. Strong high pressure centered north of the region will continue to build across the northern waters through midweek, supporting a tightening pressure gradient across most of the waters N of 17N through Thu night. This will result in a large area of fresh to strong N to NE winds across this area through late week. Near gale force N winds will develop just beyond the Baja California Norte offshore waters tonight with seas building to 12-16 ft. Seas will remain 12 ft or greater west of 130W through Thu as S swell mixes with NE wind waves. Winds are expected to diminish Fri night through the weekend as high pressure weakens and moves westward. Long period NW swell continues to propagate SE across the Pacific high seas. This swell will cover most of the waters W of 100W by Wed morning. Seas of 8-10 ft will persist in a band roughly from 05N to 16N through Thu in mixed swell. Elsewhere, cross equatorial SW swell across the far southern waters will mix with NW swell tonight through Wed night to produce 8-9 ft seas generally S of 05N between 100W and 120W. $$ Reinhart