Tropical Cyclone Discussion
235 WTPZ44 KNHC 110843 TCDEP4 Tropical Storm Norbert Discussion Number 7 NWS National Hurricane Center Miami FL EP142026 1100 PM HST Thu Sep 10 2026 Convection has increased and become more organized around Norbert tonight, with cloud-top temperatures below -80 C observed within the CDO. However, the tropical storm continues to contend with moderate westerly wind shear, with the center of the low-level circulation located near the western edge of the deep convection. Subjective and objective Dvorak intensity estimates have increased this evening, ranging from 45 to 59 kt. Given the improving convective organization and the higher intensity estimates, the initial intensity is set at 50 kt for this advisory. Norbert is moving westward around 13 kt along the southwestern periphery of a mid-level ridge building over the eastern Pacific. This general motion with a slightly slower forward speed is expected over the next few days as the ridge strengthens and builds westward. The forecast becomes more complex by the end of the weekend and into next week, as the strength and position of the ridge will likely determine Norbert's longer-term track. A stronger ridge would favor a west-southwestward to southwestward motion, while a weaker ridge would allow Norbert to continue moving westward for a longer period. The latest NHC forecast calls for Norbert to turn toward the west-southwest by early next week and is similar to the previous track forecast. Decreasing wind shear and sufficiently warm sea surface temperatures should support gradual strengthening over the next few days, although some mid-level dry air immediately west of the cyclone could limit the extent of the intensification. Beyond 72 h, a wide spread develops in the intensity guidance, in part because the eventual track will influence Norbert's intensity. The latest NHC intensity forecast has been raised slightly from the previous advisory through the next day or so and lies near the upper end of the intensity guidance, close to the HCCA and Google DeepMind solutions. Given the large model spread, forecast confidence is slightly below normal beyond 72 h. FORECAST POSITIONS AND MAX WINDS INIT 11/0900Z 16.6N 123.3W 50 KT 60 MPH 12H 11/1800Z 16.7N 125.0W 55 KT 65 MPH 24H 12/0600Z 17.0N 127.2W 60 KT 70 MPH 36H 12/1800Z 17.3N 129.2W 65 KT 75 MPH 48H 13/0600Z 17.9N 131.1W 65 KT 75 MPH 60H 13/1800Z 18.2N 133.1W 70 KT 80 MPH 72H 14/0600Z 18.4N 135.1W 65 KT 75 MPH 96H 15/0600Z 18.4N 139.2W 60 KT 70 MPH 120H 16/0600Z 17.4N 143.4W 55 KT 65 MPH