000 AXPZ20 KNHC 181035 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 1005 UTC Mon Nov 18 2024 Corrected Remainder of the area section 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 0945 UTC. ...SPECIAL FEATURES... Eastern Pacific Swell Event: Long-period NW swell has reached the outer offshore waters of Colima, Mexico. Seas have subsided to 8-10 ft across the Baja California offshore waters. his set of swell will continue to decay, with seas dropping below 12 ft late tonight. Another set of long-period NW swell is forecast to enter the offshore and adjacent waters N of Punta Eugenia tonight. Seas will build to 14 ft just N of the area near 31N120W and to 12 ft S of 30N offshore Baja California Norte, subsiding to below 12 ft late Tue night into early on Wed. For more details, please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https//www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from low pressure near 19N106W 1008 mb south-southeastward to 16N105W, then southwestward to low pressure near 12N115W 1011 mb. It continues to low pressure near 08N126.5W 1012 mb and to 08N136W, where it transitions to the ITCZ to beyond 07N140W. Scattered moderate to isolated strong convection is seen within 120 nm south of the trough between 115W-119W and within 30 nm of the trough between 105W-107W. Scattered moderate convection exists east of the eastern portion of the trough to 103W and N of 17N to inland Mexico near 20N. This activity is primarily being produced by the 1008 mb low pressure. Similar activity is also within 60 nm N of the trough between 108W-110W, between 136W-138W, within 30 nm of either side of the trough between 110W-115W and between 125W-134W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong high pressure and associated ridging prevail across the Baja California Peninsula offshore waters. Latest ASCAT satellite data passes show mostly moderate NW winds offshore Baja California, with the exception of the offshore waters W of the southern tip of the peninsula, and from that location to the Revillagigedo Islands where fresh to strong NW to N winds are present due to a tighter pressure gradient between the ridge and low pressure of 1008 mb that is located near 19N106W. The NW swell set W of Baja California has become fractured. Seas have lowered to below 12 ft, with peak seas to 10 ft located to the SW of the southern portion of Baja California. Moderate NW to N winds along with slight to moderate seas are over the northern and central Gulf of California while fresh to strong NW to N winds are over its southern section. Seas there are in the moderate range. Generally, gentle to moderate W to NW winds along with seas of 7-10 ft in long-period NW swell are over the remainder of the Mexican offshore waters. For the forecast, surface ridging will remain in place across the offshore waters of Baja California through mid-week. It will weaken slightly today allowing for the pressure gradient to slacken some. Looking ahead, a new set of long-period NW swell that will follow in behind a cold front will reach the waters N of Punta Eugenia, with seas to peak at around 13 ft from tonight into Tue evening, at which time the seas from the former swell event would have subsided below 8 ft. Afterward, NW winds along the Baja offshores will diminish to gentle to moderate speeds and continue through Fri night. Looking ahead, the next Gulf of Tehuantepec gap wind gale event is forecast to start Wed night. Gale force winds and very rough seas are forecast from Wed night through early Sat. An area of low pressure located just offshore of the coast of southwestern Mexico near 19N106W with a pressure of 1008 mb is producing convection to its E as described above under the ITCZ/Monsoon Trough section. This convection is over the offshore waters of the states of Colima and Jalisco, Mexico. Development of this system is not expected due to strong upper-level winds while it moves southeastward parallel to the coast of Mexico. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh SW winds are ongoing across the Nicaragua, El Salvador and Guatemala offshore waters along with seas of 5-7 ft in mixed SW and NW swell. Gentle to locally moderate winds are across the remainder Central America offshore waters and from Ecuador to the Galapagos Islands. Seas are slight to moderate in mixed SW and NW swell across these waters. Otherwise, scattered to numerous showers and thunderstorms, some heavy, are evident over the offshore waters of Guatemala, El Salvador and northern Nicaragua. This activity is on the outer SW fringes of the remnant cyclonic circulation from former Tropical Storm Sara. For the forecast, moderate to fresh SW winds over the offshore waters from Nicaragua to Guatemala will change little through Tue, then diminish slightly on Tue night. Gentle to moderate winds along with slight to moderate seas are expected elsewhere through the end of the week. Looking ahead, a gale gap wind event is forecast to begin in Tehuantepec Wed night. Fresh to strong winds and very rough seas associated with this event are forecast to affect the far western Guatemala offshore waters Thu through Fri. ...REMAINDER OF THE AREA...Corrected Please refer to the Special Features sections for details about large swell propagating through the NE forecast waters. A tight pressure gradient related to a strong high pressure center of 1037 mb that is located well NW of the discussion area near 40N148W supports a large area of fresh to strong NE to E winds from 08N to 21N W of 120W, where seas are 8-10 ft, the highest being W of 138W. Mostly fresh NE winds are N of 20N along with seas of 7-9 ft in long-period N to NE swell. Gentle to moderate winds along with seas of 6-8 ft due to long-period NW swell are south of the monsoon trough to 05N, and seas of 5-7 ft are S of 04N. For the forecast, the high pressure will be reinforced by another strong area of high pressure tonight. As a result, fresh to strong winds will continue to affect most of the waters N of 08N and W of 120W today and early this evening. Large long- period NW swell will continue to propagate across the forecast region. Seas of 8-12 ft will persist over the west-central waters through early this afternoon due to a combination of N to NE swell and wind generated waves. Seas in excess of 8 ft are forecast to cover most of the waters N of 05N and W of about 100W through late Tue night before subsiding. $$ Aguirre