{"id": "1209995879159595010", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-13T21:00:00Z", "msg": "374\nWTPZ44 KNHC 132037\nTCDEP4\n \nTropical Storm Norbert Discussion Number  17\nNWS National Hurricane Center Miami FL       EP142026\n1100 AM HST Sun Sep 13 2026\n \nVisible satellite imagery indicates that Norbert\u2019s center has become \nexposed. The bulk of the convection is located on the south and east \nsides of the storm. Water vapor imagery shows that a good amount of \ndry air has penetrated into the core of the cyclone. The latest TAFB \nDvorak fix estimated the intensity around 45 kt and the objective \nintensity estimates from UW-CIMSS are in the range of 32-39 kt. In \naddition, recent ASCAT pass shows that the strongest winds close to \nthe center were around 37 kt. Therefore, the initial intensity has \nbeen lowered to 40 kt for this advisory.\n \nThe initial motion is estimated to be 290/11 kt. The storm is\nexpected to move west-northwestward to westward as it moves to the\nsouth of a low- to mid-level subtropical ridge. The track guidance\ncontinues to have good agreement on the general heading for this\nstorm. The current NHC track forecast has been nudged slightly to\nnorth of the previous forecast track and remains close to the \ncorrected multi-model consensus (HCCA) and the Google DeepMind \n(GDMI) ensemble mean.\n \nMore fluctuations in intensity are possible in the short term as \nNorbert remains in a marginal environment. The cyclone continues to \ncontend with mid-level dry air intrusions and light west- \nsouthwesterly vertical wind shear.  After 12 h, the wind shear \nis expected to increase, which should result in a gradual weakening. \nAround 60 h, the simulated GFS and ECMWF satellite imagery shows \nthat the cyclone should lose organized deep convection and it is \ntherefore expected to become a post-tropical remnant low and then \ndissipate by around 72 h. The current NHC intensity forecast \nremains in line with the latest guidance including the HCCA and \nGDMI consensus guidance.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  13/2100Z 18.8N 134.0W   40 KT  45 MPH\n 12H  14/0600Z 19.2N 136.0W   40 KT  45 MPH\n 24H  14/1800Z 19.7N 138.6W   35 KT  40 MPH\n 36H  15/0600Z 20.2N 141.4W   35 KT  40 MPH\n 48H  15/1800Z 20.7N 144.0W   30 KT  35 MPH\n 60H  16/0600Z 20.8N 146.9W   25 KT  30 MPH...POST-TROP/REMNT LOW\n 72H  16/1800Z...DISSIPATED\n \n"}