000 AXPZ20 KNHC 131600 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon May 13 2019 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 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from a 1010 mb low over northwest Colombia near 10N74W to 07N80W to 08N89W to 08N100W to 06N110W and to 06N118W, where latest scatterometer data indicates that it transitions to the ITCZ and continues to 05N130W and to just east of a trough at 08N139W. Scattered moderate to strong convection exists within 120 nm south of the trough between 111W and 116W. Scattered moderate to isolated strong is within 90 nm north of the trough, and also within 60 nm south of the trough between 104W and 107W. Scattered moderate convection is within 90 nm north of the trough between 113W and 116W, and within 60 nm north of the trough between 109W and 113W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad and weak ridge extends from a 1020 mb high pressure centered near 32N127W southeastward through the Revillagigedo Islands to near 14N106W. The pressure gradient between it and lower pressure over Mexico is allowing for only moderate northwest winds to exist across the Mexican offshore waters north of 20N. However, the exception to this will occur along the prominent coastal capes and points such as Punta Eugenia, Cabo San Lazaro, Cabo San Lucas and Cabo Corrientes, where fresh or even briefly strong northwest winds are possible through Tue. These winds will continue near Cabo San Lucas through the remainder of the week. Overnight satellite altimeter data suggested seas of 4-6 ft occurring across the offshore waters of Baja California, and 6-8 ft farther southeast between Cabo Corrientes and the Revillagigedo Islands. These higher seas are due to cross equatorial southwest swell that have reached the area and are mixing with moderate northerly wind waves. Little change in this wind pattern is expected through Wed, while seas while seas will increase area-wide by about 1 ft today as the southwest swell peaks today through this evening, then gradually subside through Wed. Farther southeast, smoke from agricultural and forest fires over much of southern Mexico is impacting the offshore waters along the coast of Mexico from the southeast part of the Gulf of Tehuantepec to near Manzanillo, and will periodically reduce visibilities to near 5 nm. Marine conditions remain fairly, with gentle southerly winds across far north portions and gentle to moderate northwest winds across the south half of the basin. Beyond Wed, a weakening front will move into the waters off Baja California Norte Thu through Fri. The main impact of this system currently appears to be northwest swell of 5-7 ft moving into the waters off Baja California Norte, while fresh to strong southwest gap winds funnel into the northern portion of the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A very weak pressure gradient continues across the far eastern Pacific tonight. Recent scatterometer data showed light to gentle southwest to west onshore wind flow prevailing across most of the waters. The main marine impact across the region continues to be long period southwest swell, which will support offshore wave heights of 6-9 ft through Wed Large and powerful surf should be expected across the coasts of Central and South America and southeastern Mexico. Otherwise, little change in the wind regime is expected for the next few days. Occasional showers and thunderstorms will continue to develop off the coast from western Panama to southern Nicaragua. Agricultural fires are occurring over northern Central America. However, the low-level southerly flow is generally keeping the associated smoke over land and no significant impact on visibility is occurring over the offshore waters at this time. REMAINDER OF THE AREA... A broad and weak ridge extends from a 1021 mb high pressure system centered 31N142W southeastward to beyond the Revillagigedo Islands. This is producing a relatively weak pressure pattern, and only moderate northeast to east winds are occurring between the ITCZ and 15N and to the west of 110W. The high will shift slowly southeastward and weaken through Wed, ahead of a weak front presently approaching the northwest corner of the area. The front is expected to move over the northwestern section of the area on Wed, and continue eastward across the central and eastern sections of the area through Fri while weakening. The main impact will likely be west to northwest swell bringing waveheights in the range of 5-7 ft to the north of 25N and west of 130W through Wed. A weak trough, mainly being sustained by short-wave energy aloft riding along strong westerly flow, has formed along a position from near 14N138W to 05N139W. Scattered moderate to isolated strong convection is noted along and to the west of the trough from 07N to 11N. The gradient between the trough and high pressure to its north and northeast will allow for moderate to fresh trades from 10N to 20N west of 130W through Wed, at which time the trough is forecast to be just to the west of 140W. Waveheights are in the range of 8-10 ft to the S of 15N east of 135W are from large southwest swell propagating through this area. The swell will cover the the waters to south of 20N and east of 125W through early Tue before slowly decaying below 8 ft by Wed. $$ Aguirre