Tropical Cyclone Discussion
638 WTPZ43 KNHC 051446 TCDEP3 Hurricane Rachel Discussion Number 34 NWS National Hurricane Center Miami FL EP182026 800 AM PDT Mon Oct 05 2026 Rachel's satellite appearance continues to depict a ring of deep convection around a large eye. The system is dealing with some northeasterly wind shear, which has brought drier air that has entrained into the system and eroded some of the northern, particularly northwestern, side of the circulation. Satellite intensity estimates have decreased, with the TAFB subjective Dvorak classification a T4.5/77 kt, and using this estimate, the initial intensity is lowered to 75 kt. The system is moving westward or 275/6 kt, steered by a mid-level ridge located over the southwestern United States and eastern Pacific. This general forward motion should continue for the next several days. Toward the end of the period, a mid- to upper-level trough will move into the eastern Pacific northwest of the cyclone, causing the system to slow and make a sharp northeastward turn. The latest NHC track forecast is very similar to the previous one and continues to blend the HCCA and GDMI model solutions. Rachel is traversing marginally warm sea surface temperatures of around 26-27C while dealing with some shear and drier air. Given recent structural changes, there will likely be fluctuations in intensity over the next day or so. Beyond 36 to 48 h, sea surface temperatures cool along the forecast track, which, combined with increasing dry air, will induce a more steady weakening trend. Determining when Rachel becomes post-tropical has been tricky, as the aforementioned trough that will turn the system northeastward may induce some baroclinic support to maintain convection. Simulated infrared imagery shows that convection may become less organized by day 5, and the latest NHC forecast now depicts the system becoming post-tropical at that time. The latest NHC intensity forecast remains at the high end of the guidance envelope near the HCCA and GDMI in the short term, then trends closer to the rest of the consensus aids as the system weakens through the end of the forecast period. FORECAST POSITIONS AND MAX WINDS INIT 05/1500Z 20.4N 116.2W 75 KT 85 MPH 12H 06/0000Z 20.5N 117.3W 75 KT 85 MPH 24H 06/1200Z 20.5N 118.9W 70 KT 80 MPH 36H 07/0000Z 20.7N 120.2W 70 KT 80 MPH 48H 07/1200Z 21.1N 121.7W 65 KT 75 MPH 60H 08/0000Z 21.7N 123.1W 60 KT 70 MPH 72H 08/1200Z 22.0N 124.6W 50 KT 60 MPH 96H 09/1200Z 22.4N 126.6W 45 KT 50 MPH 120H 10/1200Z 23.1N 125.5W 35 KT 40 MPH...POST-TROPICAL