{"id": "1209428991846318082", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-11T21:00:00Z", "msg": "982\nWTPZ44 KNHC 112033\nTCDEP4\n \nTropical Storm Norbert Discussion Number   9\nNWS National Hurricane Center Miami FL       EP142026\n1100 AM HST Fri Sep 11 2026\n\nNorbert's satellite presentation has changed little over the past \nfew hours. The cyclone continues to be defined by a shield of deep \nconvection, with an outflow band evident across its northern \nquadrants. The latest subjective Dvorak estimate from TAFB is \nT3.5/55 kt, and objective intensity estimates from UW-CIMSS range \nbetween 50 and 61 kt. With satellite imagery and Dvorak estimates \nsuggesting a relatively steady trend, the initial intensity is \nmaintained at 55 kt.\n\nThe initial motion is estimated to be 275/12 kt. Norbert is expected \nto turn west-northwestward as a mid-level ridge to its north begins \nto weaken slightly. This general motion should continue through late \nthis weekend, after which the track models diverge significantly. \nThe track forecast is highly sensitive to the evolution of this \nridge over the next several days. The GFS shows the ridge shifting \neastward, allowing Norbert to turn northward into a more hostile \nenvironment. Conversely, the ECMWF depicts the ridge building \nsouthward, steering Norbert southwestward into a more favorable \nenvironment. Given the large spread in the track guidance, neither \nscenario is strongly favored at this time, and confidence in the \nextended track forecast is lower than normal. The official track \nforecast leans toward the southwestward solution early next week, in \nagreement with highly-skilled aids, HCCA and Google DeepMind. \nOverall, the latest NHC track forecast is little changed from the \nprevious advisory.\n\nUncertainty in the track forecast results in lower-than-normal \nconfidence in the intensity forecast. Should Norbert take a more \nnorthwestward track, it would likely weaken substantially as it \nmoves into a highly sheared environment with cooler SSTs. \nConversely, a southwestward track, as suggested by some guidance \nearly next week, would bring Norbert into a low shear environment \nover warmer waters that would favor steady strengthening. Given that \nreliable guidance currently favors the southwestward shift early \nnext week, the latest intensity forecast shows steady strengthening \ninto the weekend, followed by a brief period of weakening during \nNorbert's west-northwestward motion. This solution closely follows \nthe HCCA and lies generally above the intensity model consensus \nIVCN. \n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  11/2100Z 16.8N 125.7W   55 KT  65 MPH\n 12H  12/0600Z 16.9N 127.2W   60 KT  70 MPH\n 24H  12/1800Z 17.3N 129.1W   65 KT  75 MPH\n 36H  13/0600Z 17.7N 131.0W   70 KT  80 MPH\n 48H  13/1800Z 18.1N 132.9W   70 KT  80 MPH\n 60H  14/0600Z 18.3N 134.8W   65 KT  75 MPH\n 72H  14/1800Z 18.4N 136.8W   60 KT  70 MPH\n 96H  15/1800Z 18.2N 141.2W   55 KT  65 MPH\n120H  16/1800Z 16.7N 145.5W   55 KT  65 MPH\n \n"}