462 AXPZ20 KNHC 140359 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Sep 14 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...TROPICAL WAVES... A weak tropical wave is along 121W from 04N to 15N moving westward at around 10 kt. Isolated moderate convection is west of the wave axis from 09N to 14N between 121W and 126W. This tropical wave is likely to become diffuse later today. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northern Colombia near 08N74W to 11N96W to 07N113W to 10N125W to 14N133W to 13N140W. Scattered moderate convection is from 05N to 13N east of 107W. Numerous moderate to isolated strong convection from 10N to 16N between 128W and 136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A trough is forecast to meander southwest of the Baja California Peninsula through Sun night. Generally low pressure across Mexico and a weak pressure gradient in the region will support gentle to moderate winds in the Gulf of California through the upcoming weekend. Seas are forecast to be 3 ft or less, except 3 to 5 ft near the entrance of the Gulf due to long period southerly swell. Gentle to moderate NW flow will prevail across the offshore waters W of Baja California through Sat morning, with seas generally in the 5 to 7 ft range. The pressure gradient will slightly tighten on Sat, which will result in moderate to fresh NW winds with seas to 8 ft in the Baja California Norte offshore waters. Long period southerly swell will continue to impact the entrance of the Gulf of California, and the waters W of Baja California through Tue. An area of low pressure is expected to develop well south of the southwestern coast of Mexico over the weekend. Thereafter, environmental conditions appear conducive for gradual development, and a tropical depression could form while the system moves generally westward to west-northwestward at 10 to 15 mph south of Mexico. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone developing through 48 hours, and a medium chance through 5 days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will meander between 08N and 10N during the next several days. Winds on both sides of the trough axis will be gentle to moderate. Winds are forecast to increase to moderate to fresh S of the axis and roughly between 96W and 106W today in the afternoon into Sun morning as broad low pressure along the axis deepens slightly. Winds during this period will extend to 116W. Pulses of cross-equatorial southerly swell continue to reach the coasts of Mexico and Central America. Seas of 8 to 9 ft are already affecting the waters between Ecuador and the Galapagos Islands. Seas will further build to 10 ft reaching the Azuero Peninsula Sat. This swell event will start to decay late on Sun. REMAINDER OF THE AREA... The remnant low of Paul with a central pressure of 1009 mb is near 22N132W. Latest scatterometer data continue to show fresh to strong winds within 180 nm NW quadrant of the low along with 8 to 9 ft seas. The remnant low of Paul will move westward with the associated winds and seas gradually diminishing through 48 hours. Paul should open up into a trough by Sat night. Looking ahead, an area of low pressure is expected to develop well south of the southwestern coast of Mexico over the weekend. Thereafter, environmental conditions appear conducive for gradual development, and a tropical depression could form while the system moves generally westward to west-northwestward at 10 to 15 mph south of Mexico. Currently, this system has a medium chance of tropical cyclone formation through 5 days. $$ Ramos