{"id": "1209076389527027714", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-10T15:00:00Z", "msg": "562\nWTPZ44 KNHC 101440\nTCDEP4\n \nTropical Storm Norbert Discussion Number   4\nNWS National Hurricane Center Miami FL       EP142026\n800 AM PDT Thu Sep 10 2026\n\nAn AMSR-3 microwave pass over Norbert and GOES-West Infrared \nsatellite imagery indicate that the low-level center of Norbert is \nunderneath the western side of main burst of convection associated \nwith Norbert's developing core.  Moderate westerly wind shear is \nhaving a significant affect on the cyclone by pushing the majority \nof the convection to the east of the low-level center.  Given that \nthe center is underneath the convection, gradual intensification \nseems possible in the short term.  The latest subjective Dvorak \nclassification from TAFB is T2.5/35 kt, and recent objective \nintensity estimates from UW-CIMSS range from 35-40 kt. The initial \nintensity is held at 35 kt.\n\nThe initial motion estimate is westward, or 275/12 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 similar to the previous one, and lies close to the 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 few days while the system moves into a \nsufficiently moist environment over waters near 28C.  Despite these \nseemingly favorable conditions, there are mixed signals in the \nguidance regarding how much strengthening may occur.  There is also \na large spread in some of the ensemble intensity guidance.  For \nexample, the Google DeepMind ensemble has a spread at day 4 that \nranges from 30 to 120 kt.  The HAFS-A keeps it a tropical storm \nthrough the forecast period.  The HAFS-B briefly makes it a category \n1 hurricane within the next 60 hours before weakening the system \nback to a low-end tropical storm by day 4-5.  The NHC intensity \nforecast is similar to the previous one, showing a slightly faster \nintensification in the first 48 hours, but then a slower rate of \nstrengthening thereafter.  The NHC intensity forecast still lies on \nthe higher end of the guidance envelope and calls for Norbert to \nreach hurricane strength by early next week.\n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  10/1500Z 16.5N 119.3W   35 KT  40 MPH\n 12H  11/0000Z 16.5N 121.2W   40 KT  45 MPH\n 24H  11/1200Z 16.5N 123.7W   45 KT  50 MPH\n 36H  12/0000Z 16.6N 125.9W   50 KT  60 MPH\n 48H  12/1200Z 17.0N 127.9W   55 KT  65 MPH\n 60H  13/0000Z 17.4N 129.7W   55 KT  65 MPH\n 72H  13/1200Z 17.9N 131.4W   60 KT  70 MPH\n 96H  14/1200Z 18.4N 134.7W   65 KT  75 MPH\n120H  15/1200Z 18.3N 138.2W   65 KT  75 MPH\n \n"}