000 AXPZ20 KNHC 090708 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Mar 9 2023 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 0640 UTC. ..SPECIAL FEATURES... The large scale environment is favorable for heavy rainfall over portions of NW South America through Saturday. Five day rainfall totals may exceed 250 mm over interior portions of Piura and northern Lambayeque in Peru, and in the Gulf of Guayaquil region in southern and central Ecuador. In addition, above average precipitation is expected in western Colombia with rainfall totals in excess of 200 mm possible, and in southern Costa Rica where rainfall totals may exceed 150 mm. Please refer to your local meteorological service for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from Panama near 09N79W to 05N94W to 02N112W. The ITCZ extends from 00N120W to southwest of the area. Scattered moderate convection is noted from 05N to 03.4S between 77W and 84W, from 10N to 13N between 86W and 87.5W, and from 01S to 03.4S between 90W and 97W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge of high pressure extends northwest to southeast across the offshore waters of Mexico. Moderate to fresh winds are noted west of the Baja California peninsula per recent ASCAT scatterometer data. Gentle to moderate winds prevail elsewhere. Seas are in the 6 to 8 ft range offshore Baja California per recent altimeter passes, with seas of 3 to 6 ft elsewhere over the open waters off Mexico. Over the Gulf of California, seas are in the 1 to 2 ft range, reaching 3 ft at the entrance to the Gulf. Some haze continues to be reported at coastal sites of southern Mexico. For the forecast, moderate to fresh N winds in the Gulf of Tehuantepec will diminish this afternoon. Moderate to fresh NW to N winds will prevail offshore Baja California through the upcoming weekend and into early next week, locally strong near and north of Punta Eugenia at times. Winds will pulse to moderate or fresh in the central and southern Gulf of California during the afternoon and overnight hours through the weekend and into early next week. Winds will be mainly moderate or weaker across the remainder of the waters. NW swell will support seas greater than 8 ft offshore Baja California through Thu morning. A new set of NW swell may build seas to around 8 ft offshore Baja California by the end of the weekend into early next week. Little change in seas is forecast elsewhere. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please refer to the Special Features section for details on the potential for heavy rainfall over NW South America through Saturday. Moderate to fresh NE to E winds are in the Gulf of Papagayo, along with 5 ft seas per recent altimeter data. Winds are gentle to moderate elsewhere per recent ASCAT scatterometer data. Outside of the Gulf of Papagayo, seas are in the 3 to 5 ft range in S to SW swell, except 2 to 4 ft offshore Colombia. Some haze continues to be reported at coastal sites of Guatemala and El Salvador. For the forecast, moderate to fresh winds will pulse in the Gulf of Papagayo through early Sun. Winds will be moderate or weaker elsewhere, except moderate to fresh south of western Panama Fri night through Sat. Seas will build to 4 to 6 ft in S to SW swell form offshore Ecuador to offshore Galapagos Islands Fri through early next week, with little change in seas elsewhere. Active convection will continue offshore western Panama and Costa Rica with locally higher winds and seas possible. REMAINDER OF THE AREA... A system west of 140W is spreading associated fresh to strong S to SW winds and seas to 8 ft north of about 27N and west of 129W. Otherwise, high pressure prevails across the waters north of the Equator with gentle to moderate winds. Seas are 7 to 8 ft in decaying NW swell north of 10N between 110W and 125W. Seas are mainly 5 to 7 ft in NW to N swell elsewhere, except 4 to 6 ft mixed with SW swell east of 95W. For the forecast, the NW swell over the NE and central waters will continue to decay today. A frontal system approaching 140W will support fresh to strong SW winds and seas of 8 ft or greater ahead of it, spreading southeast of 30N through tonight. The seas of 8 ft or greater will continue eastward reaching to near 125W by the weekend, and with seas of 12 ft or greater briefly north of 20N and west of 136W Fri night into early Sat. Little change in winds is forecast elsewhere through the upcoming weekend, with fairly tranquil conditions expected for the start of next week. $$ Lewitsky