000 AXPZ20 KNHC 141557 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1557 UTC Mon Aug 14 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVES... A tropical wave extends along roughly 91W north of 10N into central Guatemala, moving west at 10 to 15 kt. Scattered moderate convection is noted within 60 nm of the coast from El Salvador to southern Mexico, although this is related more to lingering overnight coastal convection and will dissipate this afternoon. A tropical wave extends from 1009 mb low pressure along the monsoon trough near 13N104W to 19N106W. Scattered moderate convection is ongoing from near the monsoon trough from 09N to 13N between 100W and 105W. Both the low and wave are expected to continue on a general WNW track during the next few days. Gradual development of this low/tropical wave is anticipated through early next week. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N85W to 13N104W to 15N133W to 11N140W. Other than the convection noted in the tropical wave section above, scattered moderate convection is found within 120 nm south of the axis between 90W and 95W, within 60 nm either side of axis from 115W to 125W and within 90 nm south of the axis west of 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Post-tropical Cyclone Jova is centered near 20N122W at 14/1500 UTC with 20 to 25 kt winds and seas to 8 ft. Convection has completed dissipated as the remnant low has moved over cooler waters. The remnant low pressure is forecast to weaken and dissipate by Thursday evening. Otherwise, a gentle to moderate breeze will prevail in the vicinity of the northern and central Baja California Peninsula through mid week, increasing to moderate to fresh by the end of the week as the pressure gradient tightens slightly. Long period southerly swell are propagating toward the coast of southern Mexico. Seas are peaking between 7 and 9 ft in the offshore waters south of 14N. The swell will decay and seas will begin to subside below 8 ft beginning tonight. Fresh to strong northerly winds may pulse over the Gulf of Tehuantepec during the late night and early morning hours Thursday night through Saturday night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Nocturnal offshore winds will pulse to fresh in the Gulf of Papagayo through mid-week, then increase to fresh to strong thereafter. Otherwise, moderate S to SW winds are expected south of the monsoon trough, with mainly light to gentle variable winds prevailing N of the trough through Friday night. Long period southerly swell and 6 to 9 ft seas will continue across the region this evening and tonight, but will decay to below 8 ft Tuesday. REMAINDER OF THE AREA... A broad surface ridge dominating the waters north of the monsoon trough will weaken in response to low pressure passing to the north through mid week. The weakening remnant low of Jova will continue WSW before finally dissipating on Thursday. The weakened ridge will allow moderate trade winds north of the monsoon trough through mid week. Persistent moderate to fresh southwest winds south of the monsoon trough have helped to create areas of 8 ft seas within 240 nm south of the monsoon trough. The winds will subside by Tuesday evening and allow the seas to subside below 8 ft. In addition to the remnant low of Jova, other weak areas of low pressure will form along the monsoon trough. One is associated with the tropical wave near 104W. This low will move WNW and drag the monsoon trough northward as it gradually develops. Expect bouts of scattered showers and thunderstorms along the monsoon trough through mid week. Seas will be 5 to 6 ft north of the monsoon trough, and 6 to 9 ft south of the monsoon trough through mid week. $$ Christensen