{"id": "1217856531424247811", "title": "Tropical Cyclone Discussion", "adv_date": "2026-10-11T15:00:00Z", "msg": "526\nWTPZ45 KNHC 111458\nTCDEP5\n \nHurricane Simon Discussion Number  17\nNWS National Hurricane Center Miami FL       EP202026\n900 AM CST Sun Oct 11 2026\n\nSimon continues to be a powerful Category 4 hurricane as it gets \never closer to the coast of Mexico this morning. Since the previous \nadvisory, the eye definition on infrared satellite has cooled \nslightly and the overall central dense overcast related to the \neyewall convection has been shrinking in size. There was a helpful \nGPM microwave pass at 1152 UTC, showing that the inner core is \nshowing some hints of disruption, with a larger outer band becoming \nmore dominant on Simon's northwestward side. The 12 UTC subjective \nDvorak fix was T6.5/125 kt, and the objective satellite estimates \nare in the 119-127 kt range, so the initial intensity is being \nnudged down to 125 kt for this advisory. \n\nThe hurricane has maintained a north-northwestward motion this \nmorning, or 345 degrees at 5 kt, bringing the hurricane very close \nto the coast of Mexico. On Simon's current heading, dangerous wind, \nsurge, and rainfall effects appear likely over portions of \nwest-central Mexico in the Hurricane Warning area today. It also \nremains possible the hurricane makes direct landfall between Playa \nPerula and Cabo Corrientes in the next 12-18 hours. However, like \nthe previous forecast cycle, the most reliable guidance aids   \n(HCCA, GDMI, WN3I) have shifted westward once again, and the NHC \ntrack forecast has been shifted in that direction, but due to \ncontinuity constraints is not shifted all the way to those solutions \nyet. To make matters even more uncertain, there are some \ndeterministic global model solutions (00 UTC ECMWF, 06 UTC GFS) that \nshow Simon turning southwestward near the end of the forecast \nperiod, and that is also seen in a handful of the Google DeepMind \nensemble members. This NHC track continues to favor a track that \nstays closer to the coast of Mexico before going inland into Mexico \nin 72-96 h. Needless to say, this is a low confidence track forecast \nwith higher than usual uncertainty given the spread in the \nguidance. \n\nThe intensity forecast also presents challenges. As mentioned in the \nprevious discussion, the forecast is sensitive to how close Simon \npasses to western Mexico during the next day or so. A track closer \nto the coast or inland would likely result in more severe disruption \nof Simon's circulation due to the high terrain of the Sierra Madre \nmountains, leading to rapid weakening. However, with the track \nshifting further offshore, this weakening may not be as severe, \nthough some negative topographic influence is shown in the majority \nof the guidance leading to weakening. However, like the track, the \ncurrent intensity forecast is low confidence forecast because only a \nsmall deviation either east or west could result in Simon either \ndissipating after landfall or staying much stronger than the current \nforecast offshore. The NHC intensity forecast is a compromise \nbetween these extremes. \n \nKey Messages:\n \n1. Catastrophic wind and life-threatening storm surge impacts are \nlikely along a portion of the west-central coast of Mexico, and a \nHurricane Warning is in effect from Punta San Telmo to El Roblito. \nResidents should shelter in a safe room to ride out the storm as the \nmost significant hazards with Simon are now ongoing.\n \n2. Heavy rainfall associated with Simon will impact portions of \nsouthwestern Mexico through Monday. This rainfall will produce \nlife-threatening flooding and mudslides, especially in areas of \nsteep terrain.\n \n3. Swells will affect portions of the southwestern and west-central\ncoast of Mexico over the next few days. These swells are likely to\ncause life-threatening surf and rip current conditions. Please\nconsult products from your local weather office.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  11/1500Z 19.2N 105.3W  125 KT 145 MPH...NEAR THE COAST\n 12H  12/0000Z 19.9N 105.6W  105 KT 120 MPH...NEAR THE COAST\n 24H  12/1200Z 20.5N 106.0W   85 KT 100 MPH...NEAR THE COAST\n 36H  13/0000Z 21.1N 106.4W   70 KT  80 MPH\n 48H  13/1200Z 21.8N 106.8W   60 KT  70 MPH\n 60H  14/0000Z 22.5N 106.9W   50 KT  60 MPH\n 72H  14/1200Z 23.0N 106.9W   50 KT  60 MPH\n 96H  15/1200Z 23.9N 106.4W   30 KT  35 MPH...POST-TROP/INLAND\n120H  16/1200Z...DISSIPATED\n \n"}