Tropical Cyclone Discussion
015 WTPZ44 KNHC 261434 TCDEP4 Tropical Storm Iselle Discussion Number 13 NWS National Hurricane Center Miami FL EP092026 800 AM PDT Wed Aug 26 2026 Wind shear and dry air continue to take a toll on Iselle this morning. The low-level center is fully exposed, with what little deep convection remains displaced over 100 n mi to the northeast. Earlier scatterometer data indicated winds were still around 40 to 45 kt. However, given the recent degradation in satellite appearance and decreasing subjective and objective intensity estimates, the initial intensity is lowered to 40 kt for this advisory. Iselle is expected to continue moving west-northwestward over the next few days, steered by a mid-level ridge to the north. Increasing wind shear, cooler sea surface temperatures, and a drier air mass will continue to weaken the cyclone, and it is likely to become devoid of deep convection by tonight. The latest NHC forecast follows these trends and indicates Iselle will become a post-tropical cyclone tonight. The remnant low is then expected to gradually spin down and open into a trough by day 3. The track and intensity forecasts are similar to the previous advisory, with only minor adjustments made toward the consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 26/1500Z 22.2N 124.0W 40 KT 45 MPH 12H 27/0000Z 22.5N 125.3W 35 KT 40 MPH...POST-TROPICAL 24H 27/1200Z 23.2N 127.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 28/0000Z 23.9N 128.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 28/1200Z 24.5N 130.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 29/0000Z 25.0N 132.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 29/1200Z...DISSIPATED