{"id": "1213538080296075271", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-26T09:00:00Z", "msg": "839\nWTPZ42 KNHC 260853\nTCDEP2\n \nHurricane Polo Discussion Number  23\nNWS National Hurricane Center Miami FL       EP172026\n200 AM MST Sat Sep 26 2026\n\nThe NOAA aircraft that flew in Polo from 25/22Z to 26/01Z found \nmaximum flight-level winds of 154 kt, corresponding to about 140 kt \nsurface winds using standard reduction factors.  Since that time, \nthe structure of Polo has continued to look very impressive on \nsatellite imagery.  The eye has become a bit more cloud-filled \nwith cooling infrared eye temperatures only over the last hour or \ntwo.  The latest intensity estimate from TAFB is 7.5/155 kt and \nlatest objective estimates from UW-CIMSS range from 133-153 kt.  \nThe ADT estimate of 167 kt looks a bit unrealistically too high, \ngiven some of the other observed data.  Based on the earlier recon \ndata and the recent cooling observed in the eye, the intensity is \nnudged downward slightly to 145 kt.\n\nPolo is expected to remain in a favorable environment for another \n48 hours although sea-surface temperatures and ocean heat content \nwill begin decreasing after hour 24.  As Polo approaches Baja \nCalifornia Sur, increasing southwesterly wind shear is expected to \ncause a faster rate of weakening.  The NHC intensity forecast is \nnear the high end of the model guidance suite through 48 hours.  \nThereafter, the NHC forecast lies between the middle and high end \nof the guidance.  Polo is expected to be a powerful hurricane when \nit reaches Baja California Sur, and it likely to still be a \nhurricane when it reaches mainland northwestern Mexico.\n\nThe initial motion estimate is west-northwestward, or 290 degrees at \n8 kt. There is no change to the track forecast reasoning with this \nadvisory. The hurricane is expected to turn gradually northwestward \ntomorrow, then northward by the end of the weekend while it moves \naround the western side of a ridge centered over northern Mexico. \nEarly next week an upper-level trough approaching from the northwest \nwill cause the hurricane to turn northeastward toward Baja \nCalifornia Sur and west-central Mexico. The NHC track forecast is \nvery similar to the previous advisory, and is slightly slower than \nthe latest HCCA and GDMI, but much faster than the latest TVCN \nconsensus.  The track guidance is good agreement in that there is \nvery little cross-track spread.  However, there are still some \ntiming differences (quite a bit of along-track spread).  With this \nin mind, residents in Baja California Sur and northwestern Mexico \nshould consider finishing their preparations by Sunday.\n \nDistant moisture from Hurricane Polo and Odalys will be transported\ninto the southwestern United States this weekend and early next\nweek, and may indirectly contribute to a heavy rainfall and flash\nflood threat in the region. See products issued by the Weather\nPrediction Center for more information.\n \n \nKey Messages:\n \n1. Polo is forecast to approach the west coast of the Baja\nCalifornia peninsula on Monday as a hurricane, and a Hurricane\nWatch is in effect for that region. Tropical Storm conditions\ncould reach portions of the coast as soon as late Sunday, making \nfurther preparations difficult. A storm surge will be possible, \nespecially in areas of onshore winds.\n \n2. Heavy rainfall associated with Polo may begin to impact Baja \nCalifornia Sur late Sunday into Monday. This rainfall may produce \nlife-threatening flooding and mudslides, especially in areas of \nsteep terrain.\n \n3. Dangerous surf and rip currents are likely along portions of\nthe northwest coast of Mexico and Baja California for the next \nseveral days.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  26/0900Z 17.6N 111.0W  145 KT 165 MPH\n 12H  26/1800Z 18.3N 112.1W  145 KT 165 MPH\n 24H  27/0600Z 19.7N 113.3W  135 KT 155 MPH\n 36H  27/1800Z 21.5N 113.8W  125 KT 145 MPH\n 48H  28/0600Z 23.4N 113.8W  110 KT 125 MPH\n 60H  28/1800Z 25.1N 113.2W   95 KT 110 MPH\n 72H  29/0600Z 26.9N 111.6W   75 KT  85 MPH\n 96H  30/0600Z 30.3N 107.5W   30 KT  35 MPH...INLAND\n120H  01/0600Z...DISSIPATED\n \n"}