000 AXPZ20 KNHC 122045 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2045 UTC Wed Jul 12 2017 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 2030 UTC. ...SPECIAL FEATURES... Tropical Storm Fernanda centered near 11.8N 112.2W at 12/2100 UTC or about 780 nm SSW of the southern tip of Baja California moving W at 8 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with guts to 45 kt. Numerous moderate and scattered strong convection is within 30 nm in the NE semicircle and within 90 nm in the SW semicircle. Scattered moderate and isolated strong convection is elsewhere within 270 nm in the SW semicircle. Fernanda is forecast to continue westward for the next few days, gradually strengthening to a hurricane by Friday afternoon. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 for more details. Post-tropical cyclone Eugene centered near 24.1N 122.5W at 12/2100 UTC or about 456 nm WSW of Punta Eugenia, Mexico moving NW at 9 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. No significant convection is present and Eugene has been declared a post-tropical cyclone. The remnant circulation will continue to move toward the NW for the next couple of days before dissipation. Swells generated by Eugene will continue to affect the W coast of Baja California and southern California during the next day or two causing dangerous surf and rip current conditions. See the final NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 for more details. ...TROPICAL WAVES... A tropical wave axis extends N of 09N along 97W/98W moving W at 10 to 15 kt. Associated convection is described in the section below. A tropical wave axis extends N of 08N along 84W/85W across Nicaragua and Honduras into the NW Caribbean Sea moving W at 10 to 15 kt. The majority of the associated convection is across eastern portions of Nicaragua and Honduras as well as in the Caribbean Sea. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N76W to 08N94W to 09N108W, then resumes from 11N117W to 11N132W. The intertropical convergence zone axis extends from 11N132W to 10N140W. Scattered moderate and isolated strong convection is within 90 nm N of the axis between 84W and 93W, within 150 nm S of the axis between 88W and 92W, as well as between 94W and 108W, and within 120 nm NW of a line from 11N123W to 09N132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Generally light and variable winds offshore of Baja California will become mainly northwesterly by Friday night as the remnant circulation of Eugene continues to spin down and move away from the area. Seas of 5 to 7 ft will subside to 4 to 5 ft at the same time. These conditions will then persist through the upcoming weekend with winds become light and variable again by early next week as broad troughing sets up across the offshore waters. In the Gulf of California, mainly light and variable winds will prevail, except occasionally pulsing to moderate out of the SE in the northern Gulf. Seas will be 2 ft or less, except 3 to 4 ft near the entrance. In the Gulf of Tehuantepec, northerly nocturnal winds will pulse to fresh through Saturday morning, then will be weaker thereafter. Elsewhere, mainly gentle variable winds and seas of 4 to 6 ft will prevail through the next several days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, moderate to fresh offshore nocturnal winds will pulse through Saturday morning, then will be weaker thereafter. Gentle to moderate southerly winds are expected S of the monsoon trough axis. Long period cross-equatorial southerly swell and seas 6 to 7 ft are forecast west of Colombia and Ecuador beginning on Thursday, with a reinforcing set of swell moving across the area through the upcoming weekend and into early next week. REMAINDER OF THE AREA... Please see the special features section for information on Tropical Storm Fernanda, and Post-Tropical Cyclone Eugene. Otherwise, mainly moderate trades will prevail N of the convergence zone through the next several days, except occasionally increasing to fresh in the N central waters with a tight pressure gradient present offshore of central California through the next several hours, and then redeveloping again late in the upcoming weekend and into early next week. Seas of 4 to 7 ft outside of any tropical cyclone activity will prevail, except building to 8 to 9 ft in the N central waters when the stronger winds occur. $$ Lewitsky