000 AXPZ20 KNHC 070417 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 0405 UTC Tue Sep 07 2021 Corrected Offshore Waters Within 250 nm of Mexico 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 0000 UTC surface analysis and satellite imagery through 0400 UTC. ...SPECIAL FEATURES... Gale Warning: A gale warning is in effect for the offshore waters of Mexico from Jalisco to offshore central and southern Baja California from Wed through Fri night. This is due to an area of low pressure that is located a couple of hundred miles south- southwest of Manzanillo, Mexico. The low pressure of 1009 mb is analyzed near 17N107W. Satellite imagery shows scattered moderate to isolated strong convection within 60 nm of the low center in the NE quadrant, and also from 17N to 19N between 103W- 105W. Environmental conditions appear conducive for gradual development of this system during the next few days, and a tropical depression is likely to during the next couple of days while it moves generally west-northwestward. However, outer rain bands will produce locally heavy rainfall and gusty winds along the coast of the Mexican states of Colima and Jalisco for the next day or so. This system has a high chance of becoming a tropical cyclone during the next 48 hours. Please see the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details on the gale warning and refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details on the low pressure system. ...TROPICAL WAVES... A tropical wave has its axis along 84W north of 02N to inland eastern Honduras and Nicaragua. It is moving westward at 10 kt. Large clusters of numerous moderate to isolated strong convection are ahead of the wave north of 09N east of 99W. A tropical wave has an axis along 95W north of 02N to the Gulf of Tehuantepec region and to southeastern Mexico. It is moving westward at 10 kt. No significant convection is noted. A tropical wave has its axis along 134W from 03N to 14N, moving westward at 10-15 kt. Isolated showers and thunderstorms are within 120 nm west of the wave from 10N to 12N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the coast of northwestern Colombia near 11N76W to across southern Honduras and to 12N85W to 14N96W to the Special Features low pressure near 17N107W 1009 mb, then to 14N115W to 12N125W to 12N135W and to 12N140W. Aside from the convection associated with the 1009 mb low and the tropical waves, scattered moderate convection is noted from 05N to 13N between 79W and 100W. Scattered moderate convection is also noted from 13N to 15N between 103W-107W, and within 60 nm south of the trough between 107W-110W and between 112W- 115W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO...Corrected Please see the Special Features section above for details on a recently issued gale warning due to a low pressure system centered a couple of hundred miles south-southwest of Manzanillo, Mexico. A weak trough extends from 30N120W to near 25N122W. No convection is occurring with this trough as it is surrounded by a very dry and stable environment. Latest scatterometer data depicts gentle to moderate NW winds off the Baja California peninsula with seas to 4 ft in long-period S to SW swell. In the Gulf of California, scatterometer data depicts moderate to locally fresh winds in the northern Gulf with light to gentle variable winds in the central and southern Gulf. Seas are less than 3 ft. Rather quite conditions prevail across the Gulf of California with no significant convection noted there, however scattered moderate to isolated strong convection is just inland Mexico from northern Jalisco to southern Sonora. Fresh to strong east-southeast winds are seen off the coasts of Jalisco to Guerrero due to a tight gradient between the 1009 mb low pressure system and the coast of Mexico. Earlier altimeter data showed seas up to 8 ft in that area. Otherwise, light to gentle variable winds are across the Nayarit offshores in addition to Oaxaca and Chiapas. Seas are 6 to 7 ft in long- period SW swell. Showers and thunderstorms in associated with the 1009 mb low continue across Jalisco to Guerrero. Winds will continue to be gentle to moderate off the Baja Peninsula tonight through Tue with seas to 5 ft. By Tue night, winds will become moderate to fresh as the low pressure system in the Special Features approaches the region from the SE. This system is expected to move across the offshores of the Baja Peninsula Wed through the end of the week with building seas and strong winds. In the Gulf of California, winds are expected to return to light tonight and continue through Thu night. Light to gentle winds will continue across southern Mexico. By Fri, fresh to strong winds could develop across the Gulf of Tehuantepec and continue into the weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Latest scatterometer data depicts moderate to locally fresh winds continue across the Gulf of Papagayo. Meanwhile, gentle to moderate southwest winds are south of the monsoon trough with light and variable winds are north of the monsoon trough. Seas are 3 to 6 ft in the Central American offshore waters and 6 to 7 ft seas off of Ecuador and the Galapagos Islands. Satellite imagery shows strong thunderstorms are beginning to move off of the coast of Nicaragua to Panama into the adjacent offshore waters. Isolated thunderstorms are noted along the coast of Colombia. Seas are 3 to 6 ft in the Central American offshore waters, except for higher seas of 6 to 7 ft over the waters between Ecuador and the Galapagos Islands due to a SW swell. Winds in Papagayo region will pulse moderate to locally fresh through Thu. Moderate to locally fresh SW winds are expected along the offshore waters of Costa Rica, Panama, Colombia, Ecuador and Galapagos Islands Tue through the end of the week. Seas in this area will remain in the 6 to 7 ft range, except near 8 ft seas in the region west of Ecuador. REMAINDER OF THE AREA... Broad high pressure dominates the waters north of the monsoon trough, with the gradient between it and lower pressure to the south in the monsoon trough region allowing for moderate to fresh NNE winds and seas 7 ft south of 15N and west of 115W. Gentle to moderate southerly winds remain south of the monsoon trough, with seas to 7 ft. An area of fresh winds was noted in a recent scatterometer pass near 119W. Seas to 8 ft due to a SW swell continue south of the Equator and W of the Galapagos Islands. A broad area of low pressure located several hundred miles southwest of the southern tip of the Baja California peninsula is producing disorganized showers and thunderstorms. Satellite imagery shows a cyclonic circulation at the mid-levels in this general area near 15N120W. Development of this system, if any, is likely to be slow over the next couple of days while it drifts northward. By late this week, environmental conditions are expected to become unfavorable for further development. This system has a low chance of development in the next 48 hours and 5 days. Otherwise, winds will begin to relax along the monsoon trough by Tue through the rest of the week. Moderate winds are forecast for the northern waters W of Baja California by late Tue and continuing through Thu. $$ Aguirre