Eastern Pacific Tropical Weather Discussion
875 AXPZ20 KNHC 230328 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Sep 23 2026 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 0140 UTC. ...SPECIAL FEATURES... Hurricane Polo is centered near 14.7N 101.3W at 23/0300 UTC, moving northeast at 1 kt. Estimated minimum central pressure is 905 mb. Maximum sustained wind speed is 145 kt with gusts to 175 kt. Peak seas are around 46 ft or 14.0 m. Satellite imagery shows that Polo continues to have a small eye. Numerous strong convection is noted within 120 nm in the E semicircle, and 105 nm in the W semicircle. Scattered to numerous moderate convection is noted elsewhere within 240 nm of center, except 390 nm SW semicircle. Polo is drifting toward the northeast. A slow but sharp turn to the northwest is expected to begin tonight followed by a general west-northwestward motion over the next few days. On the forecast track, the core of Polo is expected to be near the coast of southwestern Mexico through the middle of this week, although it is forecast to remain offshore. Polo is a category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale. Fluctuations in intensity are expected over the next few days, though Polo is expected to remain a very powerful major hurricane. Heavy rainfall associated with Polo will impact coastal portions of southwest Mexico through Thursday. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. Swells generated by Polo are expected to affect portions of the coast of southwestern Mexico during the next few days. These swells are likely to cause life-threatening surf, rip current conditions, and coastal flooding. Please consult products from your local weather office. Tropical Storm Odalys is centered near 15.5N 129.0W at 23/0300 UTC, moving east-northeast at 8 kt. Estimated minimum central pressure is 994 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Peak seas are near 25 ft or 7.5 m. Satellite imagery shows that its deep convection of numerous strong type intensity is within 75 nm in the E semicircle. Scattered to numerous moderate isolated strong convection is noted elsewhere within 360 nm of center, except 120 nm in the NW quadrant. Odalys is moving toward the east-northeast. An eastward to east- northeastward motion at a slightly slower speed is expected through the next couple of days, followed by a gradual turn toward the northeast then north later this week. Additional strengthening is expected, and Odalys is forecast to become a hurricane later tonight. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Polo and Odalys NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details on both systems. Heavy Rainfall over Central America: A mid to upper-level trough currently extends over the NW Caribbean while relatively warm sea surface temperatures are present, and in addition there is a potential for a Central American Gyre to form during the next several days. All of these factors will lead to enhanced moisture funneling into Central America and the Caribbean, supporting heavy rainfall through the 26th. There is still some uncertainty regarding the exact location of heaviest rainfall, but for now heavy rainfall looks likely across extreme southeastern Mexico near Chiapas, southern and central Guatemala, western Honduras, El Salvador, southern Belize well as across portions of Costa Rica and Panama. Heavy rainfall in these regions will raise concerns for life-threatening flash flooding and landslides. Please refer to local weather services as well as the International Desk at the Weather Prediction Center for more information. ...TROPICAL WAVES... The axis of a tropical wave is near 90W north of 04N, drifting slowly westward. Scattered moderate convection is noted from 01N to 07N between 81W and 94W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia to across Panama and Costa Rica, exiting the coast at 10N86W to 08N93W, then resumes well W past the circulations of Polo and Odalys, from 13N131W to 11N140W. Aside from the convection associated with Polo and Odalys and the tropical wave all discussed above, no additional convection is present. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on rapidly intensifying Major Hurricane Polo. Aside from conditions associated with Polo, moderate to fresh northwest winds are offshore Baja California while moderate or weaker winds across the remainder of the waters. Seas are 1 to 3 ft in the Gulf of California, and 4 to 7 ft over the remainder of the waters away from Polo. For the forecast, major Hurricane Polo will move to 15.0N 101.6W Wed morning, 15.9N 102.8W Wed evening, 16.4N 104.3W Thu morning, 16.6N 106.1W Thu evening, 16.8N 108.0W Fri morning, and 17.0N 110.0W Fri evening. Polo will change little in intensity as it moves to 18.2N 112.7W late Sat. Otherwise, moderate to locally fresh northwest winds will prevail across the offshore Baja California waters through early Fri morning when conditions in Baja California Sur offshores will start to deteriorate due to the proximity of Polo. Looking ahead, Tropical Storm Odalys currently well to the southwest of the southern tip of Baja California is forecast to strengthen to a hurricane and gradually approach the waters just beyond the Baja California offshore waters by the end of the upcoming weekend. Outer swells associated with Odalys will propagate into the Baja California waters and mix with those from Polo to create very confused and hazardous seas this weekend. Fresh to strong northerly gap winds may develop in the Gulf of Tehuantepec early Thu, then pulse into the upcoming weekend. Also, An area of low pressure is expected to form in a couple of days to the south of the Gulf of Tehuantepec. Afterwards, environmental conditions should be favorable for gradual development, and a tropical depression is likely to form late this week or this weekend as the system moves slowly west-northwestward to northwestward, parallel to the coast of southern and southwestern Mexico. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate or weaker winds and moderate seas prevail across the region, except for slight seas nearshore Colombia, eastern Panama and in the lee of the Galapagos Islands. For the forecast, moderate or weaker winds are expected to prevail across the offshore waters for the next several days, except becoming moderate to fresh offshore El Salvador and Guatemala Thu into early Sat as an area of low pressure is expected to form south of the Gulf of Tehuantepec in a few days. ...REMAINDER OF THE AREA... Please see the Special Features section above for details on extremely dangerous major Hurricane Polo, and on Tropical Storm Odalys. Outside of Odalys and Polo, fresh trades are over the waters roughly from 15N to 22N to the W of 133W. Seas are 7 to 10 ft in mixed northeast and southeast swell within this area of fresh trades. Moderate or weaker winds and moderate seas are elsewhere as noted in recent scatterometer and altimeter satellite data. For the forecast, major Hurricane Polo will move to 15.0N 101.6W Wed morning, 15.9N 102.8W Wed evening, 16.4N 104.3W Thu morning, 16.6N 106.1W Thu evening, 16.8N 108.0W Fri morning, and 17.0N 110.0W Fri evening. Polo will change little in intensity as it moves to 18.2N 112.7W late Sat. Meanwhile, Tropical Storm Odalys will strengthen to a hurricane near 15.5N 128.0W Wed morning, move to 15.8N 126.6W Wed evening, 16.4N 125.3W Thu morning, 17.1N 124.1W Thu evening, 17.9N 123.2W Fri morning, and 18.6N 122.9W Fri evening. Odalys will weaken to a tropical storm over 20.2N 122.6W late Sat. Very large seas generated by both systems will merge by the end of the week into the upcoming weekend as the systems get closer together resulting in very dangerous and hazardous conditions. Otherwise, high pressure over the remainder of the area will pretty much maintain moderate or weaker winds and moderate seas through the rest of the week. Looking ahead, an area of low pressure is expected to form in a couple of days to the south of the Gulf of Tehuantepec. Afterwards, environmental conditions should be favorable for gradual development, and a tropical depression is likely to form late this week or this weekend as the system moves slowly west- northwestward to northwestward, parallel to the coast of southern and southwestern Mexico.