000 AXPZ20 KNHC 102145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat Sep 10 2022 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 2130 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northwest Colombia westward to low pressure of 1010 mb near 10N79W, and continues northwestward through southern Nicaragua and El Salvador to 13N88W to 13N92W and southwestward to 10N102W to 12N120W to 14N130W to low pressure near 15N139W 1010 mb and to beyond the area at 14N140W. Scattered moderate to isolated strong convection is within 120 nm north of the trough axis between 93W-97W. Scattered moderate convection is within 120 nm south of the trough axis between 87W-91W, also between 103W-107W, between 108W-111W, between 126W-133W and between 135W-139W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The remnant low of former tropical cyclone Kay is analyzed near 31N120W with a pressure of 1004 mb. It is drifting westward. Its associated cyclonic is broad as observed in satellite imagery. The earlier fresh to strong southeast to south winds that reached south to 28N and between 116W-119W have diminished to moderate to fresh speeds per a partial ASCAT data pass from early this afternoon. Seas of 8-9 ft remain with the moderate to fresh winds due to northwest swell mixing with a south swell component. Buoy observations offshore of the border between California and the Baja California peninsula are presently reporting fresh, to at times strong, southeast to south winds and seas to 8 ft. Peak seas of 11 ft with the low are north of 30N. Areas of rain along with possible scattered showers are seen north of 29N between 117W-123W. Swells earlier generated by Kay are still affecting the coast of southern California and the northern Baja California peninsula. These swells will slowly subside into this evening as the low further weakens. Elsewhere, gentle to moderate winds are noted across the Mexico offshore waters, with an area of moderate to fresh northwest winds and seas to 8 ft across the offshore waters of Jalisco and Colima. Low pressure of 1009 mb is near 16N103W, with a trough extending from it to near 15N100W. Scattered moderate to isolated strong convection is seen from 14N to 18N between 101W-105W. Ship with call ID "VRTN4" recently reported southeast 20 kt winds at location 17N102W. For the forecast, the remnant low of Kay will continue to drift in general westward motion through this evening, then drift to the southwest through Sun morning and southeastward south of 30N afterwards through Mon as weakens. Gentle to moderate winds northerly winds will be to its west, while mainly light to gentle winds will be to its east Sun through Mon night, including the offshore waters of Baja California. High pressure will build again across the region by the middle of next week. A broad area of low pressure is likely to form near the coast of southern Mexico by early next week. Environmental conditions are expected to be conducive for some development of this system by the middle part of next week while it moves slowly westward near the coast of southern and southwestern Mexico. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone formation through 5 days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to locally fresh southerly winds and seas of 7-9 ft are noted south of the monsoon trough while light to gentle breezes and slight to moderate seas remain north of the monsoon trough. Cross equatorial south to southwest swell continues to propagate across the region. For the forecast, gentle to moderate winds and moderate seas will continue across most of the forecast area through the rest of the weekend and into the middle of next week. Seas of 8 ft due to southerly swell will subside on Sun. REMAINDER OF THE AREA... The earlier analyzed ill-defined 1010 mb low near 23N138W is now a trough that extends from near 24N139W to 22N138W and to 19N139W. No convection is noted with this trough. A rather light pressure gradient across the area is maintaining gentle winds and seas of 5-7 ft in mixed swell north of the monsoon trough to near 29N. North of 29N seas are 6-8 ft due to long-period north to northeast swell. Moderate to locally fresh south winds are present south of the monsoon trough, where seas are 7-9 ft due to south to southwest long-period swell. Latest altimeter data passes indicate seas of 9-11 ft just south of the equator between 93W-120W due to long-period southerly swell. The leading edge of 8 ft seas appears to have propagated into the coastal waters of the Galapagos Islands. For the forecast, moderate to fresh southwest winds and associated seas will continue south of the monsoon trough. Farther south, the cross-equatorial swell will continue to spread northward into tonight, then be reinforced by another pulse Sun and decay early next week. $$ Aguirre