000 AXPZ20 KNHC 290931 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat May 29 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0915 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northern Colombia near 10N74W to the coast of Costa Rica near 09N84W and to 11N91W to 09N99W to 10N104W to 10N112W and to 08N120W, where latest scatterometer data indicates that it transitions to the ITCZ and continues to 07N130W and to beyond the area at 06N140W. Scattered moderate to isolated strong convection is within 180 nm north of the trough between 96W-100W, within 120 nm south of the trough between 78W-84W and between 98W-1031W. Scattered moderate convection is within 120 nm south of the trough between 107W-111W, and within 60 nm south of the trough between 105W- 107W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends from a 1027 mb high pressure center that is northwest of the area near 32N136W southeastward to the vicinity of the Revillagigedo Islands. The associated gradient is producing moderate to fresh northwest winds across the offshore waters of Baja California mainly north of Cabo San Lazaro. Seas there are in the 5-7 ft range. The high pressure will continue to dominate the area allowing for moderate to fresh northwest winds across the waters west of Baja California through tonight. Seas are forecast to build to 7-9 ft N of Punta Eugenia as a new set of northwest swell propagates into the forecast waters and mixes with a southwest swell component. Gulf of California: Gentle to locally moderate winds will continue through the weekend along with seas of about 2-4 ft. Gulf of Tehuantepec: Mainly gentle to moderate southerly winds will continue in the Tehuantepec region through the weekend. Low pressure may form several hundred miles south of of the southeastern coast of Mexico during the next few days. This may lead to an increase in winds and seas across the offshore waters of southeastern Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Winds have become southerly in direction at gentle to moderate speeds. A small area of fresh southeast winds is present to the northwest of the Gulf near and offshore the coast of Nicaragua. Seas are in the 5-7 ft range in the Gulf of Papagayo region. Winds are forecast to become variable today through Sun night, except at times they will be southerly at at gentle speeds. Broad low pressure associated with the monsoon trough is present over the area N of northern Panama to well west of the offshore forecast waters. Gradual development of the low pressure is possible during the next few days several hundred miles offshore northern Central America, possibly leading to increasing winds and seas across the offshore forecast waters from Nicaragua to Guatemala. Mainly gentle to moderate east winds are present north of the monsoon trough, while moderate to fresh south to southwest winds are south of the monsoon trough. Seas are in the 4-7 ft range. Little change in these conditions is expected through the weekend. REMAINDER OF THE AREA... A high pressure ridge will continue to dominate the northern forecast waters through early next week. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh northeast to east winds north of the ITCZ west of about 118W. Seas are 5-7 ft across much of the open Pacific waters west of 115W, except in the far western section of the area from 10N to 17N west of 127W, where a combination of northeast wind waves and a south swell has developed seas of 8-9 ft there. By early this evening seas are expected to build to 8 ft due to increasing winds associated to a small area of low pressure along the ITCZ near 117W that is being mentioned in the Tropical Weather Outlook. A new set of long-period south-southwest swell is forecast to reach 03.4S late tonight, and continue to propagate north- northeast through the weekend building seas to 8-10 ft by late Sun roughly south of a line from 01N124W to 02N112W and to south of 03.4S at 96W. Looking ahead, a small cluster of shower and thunderstorm activity located about 870 nm south-southwest of the southern tip of the Baja California peninsula is associated with a weak area of low pressure. This system is moving westward at about 8 kt, and some slow development is possible during the next few days before it moves into a drier and more stable environment early next week. The large area of shower and thunderstorm activity associated with the monsoon trough located several hundred miles south of Acapulco, Mexico presently remains disorganized. Gradual development of this system is possible during the next several days as it is forecast to slowly move west-northwestward to the south of Mexico. Southerly winds south of the monsoon trough in the vicinity of this shower and thunderstorm activity have increased in some spots to fresh to strong speeds, with seas to 8 ft. These conditions will translate westward with the aforementioned shower and thunderstorm activity as low pressure gradually develops. Seas are forecast to slowly build with time as this system acquires persistence in its duration. $$ Aguirre