Tropical Cyclone Discussion
982 WTPZ44 KNHC 112033 TCDEP4 Tropical Storm Norbert Discussion Number 9 NWS National Hurricane Center Miami FL EP142026 1100 AM HST Fri Sep 11 2026 Norbert's satellite presentation has changed little over the past few hours. The cyclone continues to be defined by a shield of deep convection, with an outflow band evident across its northern quadrants. The latest subjective Dvorak estimate from TAFB is T3.5/55 kt, and objective intensity estimates from UW-CIMSS range between 50 and 61 kt. With satellite imagery and Dvorak estimates suggesting a relatively steady trend, the initial intensity is maintained at 55 kt. The initial motion is estimated to be 275/12 kt. Norbert is expected to turn west-northwestward as a mid-level ridge to its north begins to weaken slightly. This general motion should continue through late this weekend, after which the track models diverge significantly. The track forecast is highly sensitive to the evolution of this ridge over the next several days. The GFS shows the ridge shifting eastward, allowing Norbert to turn northward into a more hostile environment. Conversely, the ECMWF depicts the ridge building southward, steering Norbert southwestward into a more favorable environment. Given the large spread in the track guidance, neither scenario is strongly favored at this time, and confidence in the extended track forecast is lower than normal. The official track forecast leans toward the southwestward solution early next week, in agreement with highly-skilled aids, HCCA and Google DeepMind. Overall, the latest NHC track forecast is little changed from the previous advisory. Uncertainty in the track forecast results in lower-than-normal confidence in the intensity forecast. Should Norbert take a more northwestward track, it would likely weaken substantially as it moves into a highly sheared environment with cooler SSTs. Conversely, a southwestward track, as suggested by some guidance early next week, would bring Norbert into a low shear environment over warmer waters that would favor steady strengthening. Given that reliable guidance currently favors the southwestward shift early next week, the latest intensity forecast shows steady strengthening into the weekend, followed by a brief period of weakening during Norbert's west-northwestward motion. This solution closely follows the HCCA and lies generally above the intensity model consensus IVCN. FORECAST POSITIONS AND MAX WINDS INIT 11/2100Z 16.8N 125.7W 55 KT 65 MPH 12H 12/0600Z 16.9N 127.2W 60 KT 70 MPH 24H 12/1800Z 17.3N 129.1W 65 KT 75 MPH 36H 13/0600Z 17.7N 131.0W 70 KT 80 MPH 48H 13/1800Z 18.1N 132.9W 70 KT 80 MPH 60H 14/0600Z 18.3N 134.8W 65 KT 75 MPH 72H 14/1800Z 18.4N 136.8W 60 KT 70 MPH 96H 15/1800Z 18.2N 141.2W 55 KT 65 MPH 120H 16/1800Z 16.7N 145.5W 55 KT 65 MPH