Tropical Weather Discussion
Issued by NWS
Issued by NWS
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501 AXPZ20 KNHC 220300 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Sep 22 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 0130 UTC. ...SPECIAL FEATURES... Hurricane Polo is centered near 15.0N 102.3W at 22/0300 UTC, moving east-southeast at 4 kt. Estimated minimum central pressure is 964 mb. Maximum sustained wind speed is 95 kt with gusts to 115 kt. Peak seas have risen up to near 30 ft or 9.0 m, and may be higher already. Satellite imagery shows that Polo has an eye on infrared images, with very deep convection wrapping around an eyewall. Numerous strong convection is present within 120 nm in the E semicircle, 210 nm in the SW quadrant, and 90 nm in the NW quadrant. Scattered moderate isolated strong convection is noted elsewhere within 0 nm in the NE quadrant, 210 nm in the SE and NW quadrants, and 270 nm in the SW quadrant. Polo is moving toward the east-southeast. This general motion is expected to continue overnight, with a sharp turn toward the northwest and west-northwest anticipated late Tue into Wed. On the forecast track, the core of Polo is expected to be near or south of the coast of southwestern Mexico during the next few days. Rapid intensification is forecast over the next day or so, and Polo is expected to become a major hurricane shortly, and a potentially catastrophic Category 5 hurricane by Wed. 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 begin affecting portions of the coast of southwestern Mexico on Tue. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. Tropical Storm Odalys is centered near 14.3N 130.3W at 22/0300 UTC, moving west-northwest at 6 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas are near 18 ft or 5.5 m. Satellite imagery shows deep convection with numerous moderate to strong convection seen within 45 nm of the center, except within 150 nm in the SW quadrant. Numerous moderate isolated strong convection is seen elsewhere within 360 nm in the NE quadrant, 510 nm in the SE quadrant, 990 nm in the SW quadrant, and 150 nm in the NW quadrant. Odalys is moving toward the west-northwest. A turn toward the north is expected tonight, followed by a gradual turn toward the east-northeast and east through midweek. Some strengthening is forecast during the next couple of days, and Odalys is forecast to become a hurricane by mid-week. 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 NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details on both systems. Heavy Rainfall over Central America: Over the next several days, the potential development of a Central American Gyre (CAG) is expected. This CAG along with warm Sea Surface Temperatures will fuel an enhanced amount of moisture in the region and deepen convection over land, while a deep mid to upper level trough extends over the western Caribbean. It is too early to determine exact rainfall amounts. Please consult products from your local weather office. ...TROPICAL WAVES... The axis of a tropical wave is near 89W north of 02N, moving westward at around 10 kt. Nearby convection is described below with the monsoon trough. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the SW Caribbean Sea northwestward to across portions of Central America, and is not present over the discussion waters east of 140W due to the circulations of Hurricane Polo and Tropical Storm Odalys. Other than the convection associated with those systems and described above, scattered moderate isolated strong convection is noted from 00N to 15N between 77W and 90W. Scattered moderate convection is noted from 08N to 12N between 116W and 119W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on Hurricane Polo. Aside from conditions associated with Polo, moderate to fresh NW winds are offshore Baja California with moderate or weaker winds across the remainder of the waters. Seas are 1-3 ft in the Gulf of California, and 4-7 ft across the remainder of the waters away from Polo. For the forecast, Polo will move to 14.9N 101.8W Tue morning, 15.1N 101.7W Tue evening, 15.6N 102.2W Wed morning, 16.5N 103.2W Wed evening, 17.3N 104.5W Thu morning, and 17.7N 106.0W Thu evening. Polo will change little in intensity as it moves to 18.6N 109.2W late Fri. Otherwise, moderate to locally fresh NW 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 could form in a few days to the south of the Gulf of Tehuantepec. Thereafter, environmental conditions appear favorable for gradual development, and a tropical depression could form late this week or this weekend while 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 slight seas nearshore Colombia, eastern Panama and in the lee of the Galapagos Islands. Very active convection is present across much of the offshore waters due to a passing tropical wave described above. Locally higher winds and seas may be in and near any convection. For the forecast, moderate or weaker winds are expected to prevailacross 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 may form just west of the area. ...REMAINDER OF THE AREA... Please see the Special Features section above for details on Hurricane Polo and on Tropical Storm Odalys. Outside of Odalys and Polo, fresh to strong winds, and rough seas, are over the waters from 15N to 25N and west of 133W due to a tight gradient between high pressure over the northwest portion of the area, Odalys and a remnant low pressure west of 140W. Moderate or weaker winds and moderate seas prevail elsewhere. For the forecast, Hurricane Polo will move to 14.9N 101.8W Tue morning, 15.1N 101.7W Tue evening, 15.6N 102.2W Wed morning, 16.5N 103.2W Wed evening, 17.3N 104.5W Thu morning, and 17.7N 106.0W Thu evening. Polo will change little in intensity as it moves to 18.6N 109.2W late Fri. Meanwhile, Tropical Storm Odalys will move to 14.8N 130.1W Tue morning, 15.1N 129.3W Tue evening, strengthen to a hurricane near 15.2N 128.1W Wed morning, 15.5N 126.8W Wed evening, 16.1N 125.4W Thu morning, and 16.8N 124.3W Thu evening. Odalys will change little in intensity as it moves to 18.3N 122.4W late Fri. 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. $$ Lewitsky