000 AXPZ20 KNHC 121920 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Jun 12 2024 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 1800 UTC surface analysis and satellite imagery through 1840 UTC. ...TROPICAL WAVES... A tropical wave is in the far eastern portion of the tropical eastern Pacific Ocean along 79W, from 14N in the SW Caribbean Sea to across the Gulf of Panama to near the border of Colombia and Ecuador, moving west at 10 to 15 kt. Scattered moderate isolated strong convection is noted from 03N to 09N between the coast of Colombia and 86W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 13N87.5W to 08.5N110W to 07N118W to 10N134W to 08N137W. The ITCZ extends from 08N137W to 07N140W. Widely scattered to numerous moderate and isolated strong convection is from 05N to 17N between 87W and 106W. Scattered moderate convection is from 04N to 08N between 106W and 112W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure centered well NE of Hawaii extends a ridge southeastward to near the Revillagigedo Islands. This pattern supports moderate to locally fresh NW to N winds across the Baja offshore waters between Punta Eugenia and the Revillagigedo Islands, as indicated by a recent ASCAT scatterometer pass, and gentle to moderate NW winds to the north of Punta Eugenia. Seas are generally 5 to 7 ft in NW swell. A surface trough extends across the Gulf of California along 110W to south of Baja California. Mainly moderate winds are on either side of the trough in the central and southern Gulf of California, with light and variable winds in the northern Gulf of California. Seas are 1 to 3 ft in the Gulf of California, except to 4 ft near the entrance. Gentle to moderate winds dominate the remainder of the Mexican offshore waters, with seas of 4 to 6 ft in mixed SW and NW swell. Widely scattered to numerous showers and thunderstorms persist across the waters south of 17N and east of 105W. North of 12N away from any convection and extending to offshore Jalisco, smoke from agricultural fires may be restricting visibility somewhat over area waters. For the forecast, troughing will extend from the Gulf of California to near the Revillagigedo Islands with broad ridging northwest of there. A relatively tight pressure gradient will yield an increase in winds on both sides of the troughing through the next several days. NW swell will impact waters offshore Baja California at the end of the week into the weekend, leading to seas of 8 to 13 ft north of Cabo San Lazaro by the end of the weekend. A broad area of low pressure could form late this week a couple of hundred nautical miles off the coast of southern Mexico or Guatemala. Some slow development is possible this weekend and early next week while the system meanders near the coast. Thunderstorms will impact the waters offshore southern Mexico through the upcoming weekend. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough remains located farther north than its usual position for this time of year, and currently extends along the coasts of Guatemala and El Salvador to across Nicaragua. Gentle to moderate southerly winds prevail across area waters. Seas are generally 4 to 7 ft in SW swell, except 3 to 5 ft inside the Gulf of Panama and in the lee of the Galapagos Islands. Widely scattered showers and thunderstorms continue across the regional offshore waters north of Ecuador in the moist, monsoonal southerly flow, along with a tropical wave which has emerged offshore Colombia through the Gulf of Panama. For the forecast, monsoonal winds, associated seas, and numerous thunderstorms will dominate the region through at least the remainder of the week. A broad area of low pressure could form late this week a couple of hundred nautical miles off the coast of southern Mexico or Guatemala. Some slow development is possible this weekend and early next week while the system meanders near the coast. This will allow for the monsoon trough to lift even farther northward toward the Gulf of Tehuantepec, with winds to the west of 90W increasing to fresh to locally strong, leading to building seas of 8 to 12 ft at times, highest late weekend into early next week. Thunderstorms will impact a large portion of the offshore waters through at least the end of the weekend. Meanwhile, fresh to strong SW winds are expected to develop west of Colombia Fri and shift into the Gulf of Panama Fri night and Sat before diminishing. Seas may build to around 8 ft there with these winds. Seas may also build to 6 to 8 ft west of Ecuador late in the week into the weekend in southerly swell. ...REMAINDER OF THE AREA... A frontal trough extends from 30N123W to 26.5N127W with moderate to fresh winds and seas of 7 to 9 ft behind it. A weak trough is embedded in the monsoon trough along 134W/135W from 08N to 17N. Otherwise, broad ridging dominates the waters north of the monsoon trough and ITCZ, with gentle to moderate winds and 5 to 7 ft seas in mixed swell west of 110W. To the east of 110W, fresh to locally strong winds are south of the monsoon trough north of 03N per recent ASCAT scatterometer data, along with seas of 7 to 9 ft. Mainly gentle to moderate winds and 5 to 7 ft seas in S to SW swell are elsewhere east of 110W. For the forecast, strengthening high pressure centered NW of the area will dominate waters west of 120W into the weekend. Fresh to strong winds from the California Channel Islands southward may dip south of 30N at times this weekend into early next week, with seas building to 8 to 13 ft by the end of the weekend. SW flow south of the monsoon trough is forecast to be fresh to strong into Thu between 90W and 110W, supporting seas of 7 to 10 ft. Similar winds and seas may return there by the end of the weekend into early next week. Active convection is expect to persist near the monsoon trough and east of 110W or so through at least the next couple of days. $$ Lewitsky