174 AXPZ20 KNHC 131511 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1448 UTC Thu Sep 13 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVES... A tropical wave is along 118W from 02N to 13N moving westward at around 10 kt. Only widely scattered showers and isolated thunderstorms remain with the tropical wave. This tropical wave is likely to become diffuse and difficult to track in the next 12 to 24 hours or so. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northern Colombia near 09N75W to 08N80W to 12N95W to 09N115W, then resumes from near 15N128W to 12N140W. Cluster of moderate to strong convection from 11N to 13N between 97W and 100W. Scattered moderate convection elsewhere from 09N to 16N between 92W and 101W. Similar convection is from 10N to 15N W of 130W. Scattered moderate to isolated strong convection is also noted N of 04N E of 80W to the coast of Colombia, including the Gulf of Panama. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A trough is forecast to meander between the Gulf of California and the Baja California Peninsula through Sun. As a result, gentle to moderate winds will prevail in the Gulf of California through the remainder of the week and into the upcoming weekend. Seas will be mainly 3 ft or less, except 3 to 5 ft near the entrance of the Gulf due to long period southerly swell. A gentle to moderate NW flow will prevail across the offshore waters W of Baja California, with seas generally in the 5 to 7 ft range. Winds will increase to moderate to fresh N of Punta Eugenia Fri through Sun as the pressure gradient tightens with ridging building in from the NW. Additional pulses of long period southerly swell will continue to impact the entrance of the Gulf of California, and the waters W of Baja California through the upcoming weekend. A broad area of low pressure, located about 150 miles west-southwest of Cabo Corrientes, Mexico, is producing limited shower and thunderstorm activity. Satellite imagery currently shows scattered moderate to isolated strong convection on the W semicircle of the low center mainly from 18N to 21N between 108W and 110W, and also just E of the Tres Marias Islands. This system has become less organized since yesterday, and any development of this system should be slow to occur over the next few days while the disturbance drifts west-southwestward. 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, increasing to moderate to fresh S of the axis by the end of the week into the weekend as broad low pressure along the axis deepens slightly. Additional pulses of cross-equatorial southerly swell are reaching the coasts of Mexico and Central America. Seas of 7 to 9 ft are already affecting the waters between Ecuador and the Galapagos Islands, and have also now reached to near the Azuero Peninsula. These swells will start to decay this weekend. REMAINDER OF THE AREA... The remnant low of Paul is near 22.5N131W at 1009 mb with no deep convection present. A ridge extends into the area to the NE of Paul from 31N126W to 19N120W. A tight pressure gradient is NW of Paul where another ridge axis is present with fresh to strong winds still on the NW side of the Paul along with 8 to 10 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 early Sat. 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 kt south of Mexico. $$ GR