Tropical Cyclone Discussion
293 WTPZ42 KNHC 290241 TCDEP2 Tropical Storm Lowell Discussion Number 6 NWS National Hurricane Center Miami FL EP122026 500 PM HST Fri Aug 28 2026 Lowell remains a sheared tropical cyclone this afternoon. Moderate easterly vertical wind shear continues to displace the bulk of the convection over and west of the low-level circulation center. There has been little evidence of strengthening during the past several hours, and a blend of the latest objective intensity estimates and subjective Dvorak intensity estimate from TAFB support holding the initial intensity at 40 kt for this advisory. The cyclone continues to move slowly westward, with an initial motion of about 275/5 kt. A low- to mid-level ridge is forecast to strengthen north of the cyclone during the next couple of days, which should cause the cyclone to continue westward with a gradual increase in forward speed. This general westward motion is expected to continue through the weekend and into early next week. Track forecast uncertainty increases considerably thereafter due in part to the potential influence on the steering flow from TS Karina to its northeast. There remains considerable spread in the guidance, particularly in forward speed, with the multi-model consensus (HCCA) and Google DeepMind ensemble mean generally faster than the GFS and ECMWF solutions. In addition to the along-track spread, the cross-track spread also increases considerably by day 5. Given these differences, the latest NHC track forecast reflects a blend of the previous forecast, Google DeepMind ensemble mean, and HCCA. The easterly vertical wind shear currently affecting Lowell is forecast to hold into the weekend, then steadily decrease by the latter half of the weekend, which should allow the cyclone to become better organized and gradually strengthen. However, the current sheared structure and nearby mid- to upper-level dry air should temper the rate of intensification in the short term. Environmental conditions are forecast to become more favorable thereafter, and a faster rate of strengthening is possible beginning by early next week. The intensity forecast becomes more uncertain later in the period due to Lowell's potential interaction with Karina. A faster westward track would likely keep the cyclones sufficiently separated and allow Lowell to continue strengthening, while a slower solution could expose Lowell to stronger shear associated with outflow from Karina. The latest NHC intensity forecast is similar to the previous advisory and continues to show Lowell becoming a hurricane in about 60 h. FORECAST POSITIONS AND MAX WINDS INIT 29/0300Z 12.5N 134.2W 40 KT 45 MPH 12H 29/1200Z 12.6N 135.3W 45 KT 50 MPH 24H 30/0000Z 12.7N 136.8W 50 KT 60 MPH 36H 30/1200Z 12.8N 138.6W 50 KT 60 MPH 48H 31/0000Z 13.0N 140.5W 55 KT 65 MPH 60H 31/1200Z 13.2N 142.4W 65 KT 75 MPH 72H 01/0000Z 13.4N 144.5W 75 KT 85 MPH 96H 02/0000Z 13.7N 146.9W 90 KT 105 MPH 120H 03/0000Z 14.2N 150.2W 95 KT 110 MPH