Issued at 500 AM AST Tue Oct 14 2025
000 WTNT42 KNHC 140851 TCDAT2 Tropical Storm Lorenzo Discussion Number 5 NWS National Hurricane Center Miami FL AL122025 500 AM AST Tue Oct 14 2025 Lorenzo has the appearance of a sheared tropical cyclone, with the estimated center exposed about 30 to 45 n mi outside the northwestern edge of the cyclone's main convective mass. GOES-19 proxy vis imagery suggests that Lorenzo's exposed low-level center has been moving farther away from the convection to the northwest over the past several hours. Lorenzo is struggling, even though SHIPS guidance and UW-CIMSS analyses indicate that the cyclone has reached a lower wind shear environment compared to the stronger shear it was experiencing yesterday, since the upper low to the west of Lorenzo has moved farther away. The latest subjective and objective intensity estimates range from 31-45 kt. The initial intensity will be maintained at 50 kt for this advisory based on the earlier evening ASCAT data, but if convection doesn't develop closer to the low-level center soon, then the winds could start to decrease. The initial motion estimate is northwestward, or 310 degrees at 13 kt. The northwest motion should continue today as Lorenzo approaches a weakness in the subtropical ridge. A turn to the north is expected tonight, with a northeastward motion expected Wednesday and Thursday as the storm moves around the northwestern periphery of the subtropical ridge into the faster flow regime of the mid-latitude westerlies. The NHC forecast was nudged slightly westward through the first 60 hours, and is very near the HFIP Corrected Consensus (HCCA) model during that time period. Thereafter, the forecast is more or less similar to the previous NHC prediction, showing a partial clockwise loop from days 3-5, as Lorenzo (or its remnants) rotate southeastward and then southwestward around the aforementioned subtropical high. Yesterday, some of the global and regional models like the GFS, HWRF and HMON, as well as some of the ECMWF and Google DeepMind ensemble members were holding onto Lorenzo through the 5-day period, even indicating some strengthening over the next few days. However, the latest cycle of global and regional models all show Lorenzo either dissipating completely or becoming a remnant low by hour 72, with fewer ECMWF and Google Deep Mind ensemble members holding onto the system compared to the previous few cycles. In fact, most of the reliable model guidance shows a steady intensity for a day or so, followed by weakening, and then dissipation in about 3 days. The new NHC intensity forecast is slightly lower than the previous prediction, but will not bite off yet on the aforementioned model solutions since Lorenzo is forecast to remain in relatively low shear and warm ocean temperatures for the next few days. The NHC intensity forecast is at the high end of the intensity guidance suite through hour 12, and then is above all of the intensity models from hour 24 onward. The intensity forecast is low confidence, and it's possible that Lorenzo could dissipate sooner than forecast. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 17.3N 44.1W 50 KT 60 MPH 12H 14/1800Z 18.4N 44.8W 50 KT 60 MPH 24H 15/0600Z 20.5N 44.8W 50 KT 60 MPH 36H 15/1800Z 23.0N 43.5W 55 KT 65 MPH 48H 16/0600Z 25.5N 41.0W 55 KT 65 MPH 60H 16/1800Z 27.9N 37.4W 50 KT 60 MPH 72H 17/0600Z 29.4N 34.0W 50 KT 60 MPH 96H 18/0600Z 28.5N 30.0W 45 KT 50 MPH 120H 19/0600Z 25.9N 32.5W 40 KT 45 MPH...POST-TROPICAL $$ Forecaster Hagen
