000 AXPZ20 KNHC 080713 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Mar 8 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 0700 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 the Gulf of Panama and Azuero Peninsula near 08N80W to 05N90W to 01N104W. The ITCZ is south of the area. Scattered moderate isolated strong convection is noted from 03N to 10N between 80W and 93W. Scattered moderate convection is noted from 01S to 03.4S between 96W and 111W. 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, reaching strong speeds within 60 nm of shore from near Punta Eugenia northward per recent ASCAT scatterometer data. Gentle to moderate winds prevail elsewhere. Seas are in the 7 to 10 ft range in NW swell offshore Baja California, 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, fresh to strong NW to N winds will prevail through the week and into the weekend near and north of Punta Eugenia. A surge of moderate to fresh NW winds will be in the central and southern Gulf of California Thu night through Fri. Winds will be mainly moderate or weaker elsewhere through the week and into the weekend. NW swell will support seas greater than 8 ft offshore Baja California through mid-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. Fresh to strong NE to E winds are in the Gulf of Papagayo per a recent ASCAT scatterometer pass, along with 5 to 6 ft seas. Gentle to moderate winds prevail elsewhere. Outside of the Papagayo region, seas are in the 3 to 5 ft range in S to SW, except 2 to 4 ft offshore Colombia. Some haze continues to be reported at coastal sites of Guatemala and El Salvador. For the forecast, fresh to locally strong NE to E winds will pulse offshore southern Nicaragua including the Gulf of Papagayo through this morning, then pulse to moderate to fresh through the end of the week and into the weekend. Seas will reach near 7 ft during the period of fresh to strong winds. Winds will be moderate or weaker elsewhere, along with seas of 3 to 5 ft in S to SW swell, except 4 to 6 ft from offshore Ecuador to offshore the Galapagos Islands. Active convection will continue offshore western Panama and Costa Rica with higher winds and seas possible. REMAINDER OF THE AREA... A tight pressure gradient due to troughing west of 140W is in the NW corner with an associated area of fresh to strong winds and seas to 8 ft. Otherwise, high pressure dominates the waters north of the ITCZ which is suppressed to south of the Equator and west of 120W. Gentle to moderate winds are found across the remainder of the open waters per recent ASCAT scatterometer data. Subsiding NW to N swell with seas of 7 to 10 ft is north of about 14N and east of 130W. 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 to N swell over the waters north of 14N will gradually decaying through tonight. Low pressure and associated fronts west of 140W are expected to continue to bring fresh to strong E to SE winds and seas of 8 to 9 ft over a portion of the NW waters today. A cold front may approach 140W by early Thu, with fresh to strong SW winds and seas of 8 ft or greater ahead of it spreading southeast of 30N through Thu night. 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 week and into the weekend. $$ Lewitsky