000 AXPZ20 KNHC 170847 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Nov 17 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Eastern Pacific Swell Event: Long-period NW swell producing seas of 10-12 ft N of 25N between 119W-124W. This set of swell will slowly decay through this evening, with seas dropping below 12 ft. Another set of long-period NW swell is forecast to enter the offshore and adjacent waters N of Punta Eugenia with seas building to 10-14 ft Mon night, and subside to below 12 ft Tue evening. 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 14N102W northwestward to low pressure of 1007 mb near 17N108W, then southwestward to 10N120W to low pressure of 1008 mb near 07N135W and transitioning to the ITCZ beyond the area at 07N140W. Scattered moderate to strong convection is seen within 90 nm NE of the trough between 106W-108W. Numerous moderate to strong convection is seen within 180 nm N of the trough between 106W-108W. Scattered moderate to isolated strong convection is within 60 nm NW of the trough between 114W-116W. Scattered moderate convection is within 60 nm of the trough W of 138W, and also within 30 nm N of the trough between 127W-133W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Strong high pressure and associated ridging prevail across the Baja California Peninsula waters. The related gradient supports moderate to fresh NW winds offshore Baja California with 8-12 ft seas N of Cabo San Lucas, highest N of Cabo San Lazaro. Gentle to locally moderate winds and slight seas are over along the Gulf of California. An overnight ASCAT satellite data pass depicted moderate to fresh NW to N winds in the Gulf of Tehuantepec region. Seas with these winds are in the range of 4-6 ft. Gentle to locally moderate winds and 5-7 ft seas in long-period NW swell dominate the remainder of the SW Mexican offshore waters, except for higher seas in the range of 6-9 ft over the offshore waters of Colima and Jalisco where the NW swell is more pronounced. For the forecast, a ridge will remain in place across the offshore waters of Baja California through the middle of the week. It will weaken slightly on Mon allowing for the gradient to slacken some. Looking ahead, a new set of long-period NW swell will reach the waters N of Punta Eugenia with seas to peak at around 14 ft from Mon night into Tue evening, at which time the seas will subside below 12 ft. The fresh winds in the Gulf of Tehuantepec region will diminish to moderate speeds today and change little through the middle of the week. Looking ahead, the next Gulf of Tehuantepec gap wind gale event may be possible starting Wed night. ...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 offshore waters along with seas of 5-7 ft in long-period NW swell. Moderate to fresh NW winds and moderate seas to 6 ft are across the offshore waters of Guatemala and El Salvador under the influence of the gap wind event in the Gulf of Tehuantepec. Elsewhere, winds are gentle to locally moderate from the SW and seas are slight in SW swell. Scattered to numerous showers and thunderstorms associated to Tropical Storm Sara located in the NW Caribbean Sea continue to affect the offshore waters of Guatemala, El Salvador and northern Nicaragua. For the forecast, the moderate to fresh SW winds over the offshore waters of Nicaragua will weaken slightly tonight as Tropical Storm Sara currently located in the NW Caribbean along the coast of Honduras moves inland Belize. Moderate seas are expected over the offshore waters from El Salvador to northern Costa Rica, including the Papagayo region today. Gentle to moderate winds along with moderate seas are expected elsewhere, except between Ecuador and the Galapagos Islands, where winds will remain at mostly light speeds. Scattered to numerous showers and thunderstorms, some possibly heavy, will continue to be quite persistent over the offshore waters of Guatemala, El Salvador, and northern Nicaragua into Mon as the onshore flow of SW winds into the outer circulation of Sara helps to sustain this activity. ...REMAINDER OF THE AREA... 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 1034 mb that is located well NW of the discussion area near 34N146W supports a large area of fresh to strong NE to E winds from 08N to 27N W of 130W and N of 13N between 120W-130W as indicated by overnight ASCAT satellite data passes. Two low pressure centers remain along the monsoon trough. Their location positions are stated above under the ITCZ/Monsoon Trough section. Gentle to moderate southeast winds along with seas of 6-8 ft due to long-period NW swell are south of the monsoon trough. A recent altimeter satellite pass indicated such values. For the forecast, the high pressure will shift slightly southeastward today will being reinforced by another strong high pressure late today. As a result, fresh to strong winds will continue to affect most of the waters N of 10N and W of 110W this weekend. Large and long period NW swell will continue to propagate across the forecast region. Wave heights to 14 ft can be expected north of 20N tonight. Seas of 12-14 ft will dominate the west-central waters tonight in a mix of NW swell and wind waves. Seas are expected to subside below 12 ft Sun night. At that time, seas in excess of 8 ft are forecast to cover much of the waters N of 05N and W of about 105W. $$ Aguirre