{"id": "1209148504417206274", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-10T21:00:00Z", "msg": "955\nWTPZ44 KNHC 102046\nTCDEP4\n \nTropical Storm Norbert Discussion Number   5\nNWS National Hurricane Center Miami FL       EP142026\n200 PM PDT Thu Sep 10 2026\n \nNorbert's structure can be described as a shear pattern, with the\nlow-level center near the western edge of the main convective area,\nwhich has persisted for a while with very cold cloud tops.  The\nTAFB intensity estimate is still 35 kt, but the objective estimates\nhave creeped up slightly, now in the 37-42 kt range.  Based on\nthose estimates, and the persistent nature of the deep convection,\nthe initial intensity estimate has been increased to 40 kt.\n \nThe tropical storm is moving westward, or 270/12 kt.  A\nwell-established mid-level ridge to the north of Norbert should keep\nthe cyclone moving in a direction between westward and\nwest-northwestward for the next several days.  The NHC track\nforecast is slightly faster toward the west than the previous\nofficial forecast and closely follows the latest HFIP Corrected\nConsensus model (HCCA).\n \nThe sheared structure of Norbert and the proximity of drier air to \nthe west of the system suggests that only modest near-term \nstrengthening should be expected.  However, the shear is forecast to \nweaken over the next 24 hours, and SHIPS guidance forecasts \nmid-level relative humidity values between 60 and 70 percent, which \nare sufficiently moist enough for strengthening.  Most of the model \nguidance does not show a large amount of strengthening and keeps \nNorbert at tropical storm strength through the next 5 days. The \nGoogle DeepMind Ensemble Mean, HCCA, and COAMPS-TC models peak \nNorbert as a Category 1 hurricane in about 3 days before bringing it \nback down to tropical storm strength by day 4 with continued \nweakening into day 5.  The new NHC forecast brings Norbert up to 65 \nkt by day 3, following the above models, and is higher than all of \nthe available intensity guidance at days 4 and 5.  Given the spread \nin the guidance, the confidence in the intensity forecast is below \naverage.\n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  10/2100Z 16.5N 120.5W   40 KT  45 MPH\n 12H  11/0600Z 16.5N 122.5W   45 KT  50 MPH\n 24H  11/1800Z 16.5N 124.9W   50 KT  60 MPH\n 36H  12/0600Z 16.6N 127.1W   55 KT  65 MPH\n 48H  12/1800Z 17.0N 129.0W   60 KT  70 MPH\n 60H  13/0600Z 17.6N 130.7W   60 KT  70 MPH\n 72H  13/1800Z 18.0N 132.4W   65 KT  75 MPH\n 96H  14/1800Z 18.4N 136.1W   60 KT  70 MPH\n120H  15/1800Z 18.3N 139.7W   60 KT  70 MPH\n \n"}