000 AXPZ20 KNHC 082205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue May 08 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 1800 UTC surface analysis and satellite imagery through 2115 UTC. ...SPECIAL FEATURE... A broad area of low pressure is analyzed as a 1012 mb surface low at 10N120W. The system is gradually becoming better organized and environmental conditions appear to be favorable for some additional development. A tropical depression could form from this system tonight or Wednesday before the disturbance moves slowly northwestward toward unfavorable upper-level winds later this week. A blend of global guidance show a surface low near 12N124W by Wednesday afternoon accompanied by gale force winds within 120 nm north semicircle of the low. Gale conditions should continue through early Sat when environmental conditions will become less favorable. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends west-southwest from the Pacific coast of Costa Rica near 09N85W to 07N91W to 12N106W through an embedded surface low at 10N120W to 06N127W. The ITCZ develops near 05N130W and continues west to beyond 06N140W. Scattered moderate isolated strong convection is observed from 10N to 14N between 98W and 114W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak surface ridge centered near 29N129W will dissipate tonight while a weak tropical low develops well southwest of the Mexican offshore waters tonight or Wed. A tightening pressure gradient between a newly developed ridge north of that low and lower pressure along the Baja California Peninsula will increase the northwest flow west of Baja Norte to a fresh breeze tonight through early Friday. Seas are forecast to build up to 10 ft during that period. The associated northerly swell will propagate as far south as 26N on Thu before beginning to subside from the south. Gulf of California: Light, mostly southerly flow forecast through Thu, except moderate nocturnal drainage flow expected near gap areas. Guidance is suggesting fresh to strong southwesterly flow developing north of 30N on Fri continuing into Sun night. Gulf of Tehuantepec: Fresh to strong gap winds will end early on Wed with winds diminishing to 20 kt or less. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to locally fresh nocturnal winds are expected through tonight, then resuming over the weekend. Gulf of Panama: Light to gentle northerly nocturnal flow is forecast through Wed. REMAINDER OF THE AREA... Refer to special features section for a warning associated with a tropical low pressure developing near 10N120W. A dissipating cold front extending from 30N132W to 24N140W will weaken to a frontal trough from 26N135W to 22N140W Wed afternoon, dissipating Wed night. Long period northwest swell in the form of 8 to 11 ft seas is expected west of the front tonight. Seas will quickly subside to 8 to 9 ft west of the frontal trough early on Wed, and further subside to less than 8 ft Wed night. Seas of 8 to 11 ft are forecast across the subtropics, generally north of 24N east of 124W late in the week. $$ Ramos