000 AXPZ20 KNHC 171556 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Jun 17 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... A surface trough of low pressure is producing a large area of disorganized showers and thunderstorms that extends several hundred miles south of the coast of southern Mexico from 04N to 18N and east of 105W. Environmental conditions appear conducive for development of this disturbance, and a tropical depression is likely to form during the next couple of days while the system moves west-northwestward or northwestward at 5 to 10 mph, near the coast of southwestern Mexico. Regardless of development, heavy rains are likely over coastal sections of the Mexican states of Oaxaca, Guerrero, Michoacan, Colima, and Jalisco during the next few days, which could cause life-threatening flash floods and mudslides. Interests in these areas should monitor the progress of this system through the weekend. This system has a high chance for tropical development within the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northwest Colombia to across northern Panama and Costa Rica and to 09N84W to 14N94W to low pres near 13N98W 1007 mb to 07N140W. Aside from the large area of scattered moderate to isolated strong convection described in the Special Features section above, scattered showers are noted along the monsoon trough between 110W-120W and 130W-140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above as the potential tropical system that is discussed is expected to develop over the offshore waters pertaining to the southwest coast of Mexico. Expect for marine conditions over most of the affected offshore waters to significantly change with this upcoming system. A surface ridge dominates the offshore forecast waters of Baja California, with the resulting gradient producing moderate to fresh northwest winds north of Punta Eugenia, including Guadalupe Island. Wave heights are in the 5-7 ft range. Light to gentle winds generally prevail elsewhere to the south and southeast with wave heights in the 3-5 ft range. The ridge will persist across the area during the next several days with mainly gentle to moderate northwest to north winds. Seas of 5-7 ft in northwest swell will continue to affect the waters north of Punta Eugenia through this afternoon, then subside a little tonight. In the Gulf of California: Gentle to moderate southerly winds will continue along with wave heights of 3 ft or less during the remainder of the work-week. Looking ahead, winds are forecast to increase to 15-20 kt across the north and central parts of the Gulf during the upcoming weekend as the pressure gradient tightens between the ridge west of Baja California peninsula and lower pressures over north-central Mexico. Wave heights are expected to build to 4-5 ft with these winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate southerly winds will continue over the offshore waters through the period. Wave heights are in the 3-5 ft range in a south to southwest swell. Wave heights are forecast to build to 6-8 ft in a southwest swell across the waters between Ecuador and the Galapagos Islands during the upcoming weekend. A broad area of low pressure located over the Bay of Campeche will continue to bring heavy rainfall over portions of Central America and southern Mexico during the next several days. Heavy rainfall could lead to flooding and mud slides across the steeper terrain of Central America. REMAINDER OF THE AREA... An area of gentle to moderate winds and seas to 9 ft prevail from 09N-12N and west of 135W. These conditions will prevail in the area through the forecast period. High pressure continues to dominate the waters roughly north of 17N and west of 125W. As high pressure builds across the forecast region, an area of fresh to locally strong northerly winds, with wave heights to 9 ft will be over the waters north of 28N between 122W-130W through this afternoon, before it begins to gradually shift westward to the northwest part of the area while expanding southward from the end of the week into the weekend. Moderate to fresh north to northeast winds are present north of 09N and west of a line from 30N124W to 09N133W. Wave heights with these winds are in the range of 5-7 ft. Southern hemispheric cross-equatorial swell is forecast to begin to propagate through the far south-central waters on Fri afternoon, and continue to spread north-northeastward into the weekend reaching to the southern portions of the offshore waters zones corresponding to southwestern Mexico. Wave heights generated by this swell are expected to be in the range of about 7-9 ft. $$ ERA