Tropical Cyclone Discussion
450 WTPA44 PHFO 312039 TCDCP4 Tropical Storm Lowell Discussion Number 17 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 1100 AM HST Mon Aug 31 2026 Moderate easterly shear is still having some affect on Lowell. Although a 31/1047Z AMSR2 pass and a 31/1459Z GPMI pass suggest that the internal structure of the convection is becoming better organized around the center, the shear needs to abate just a bit more, in order for the low- and mid-level centers to better align vertically, before the cyclone can strengthen significantly. The latest subjective Dvorak estimates from PHFO and JTWC range from 45-65 kt, and objective estimates have been ranging from 45-50 kt. The initial intensity is held at 55 kt based on a blend of the intensity estimates. The initial motion is just south of due west, or 265 degrees at 11 kt. A mid-level ridge north of Lowell will be the primary steering mechanism for the next few days. Lowell should move generally westward to west-northwestward during that time. By day 4 and 5, Lowell could gain some latitude as it feels some pull from a mid- to upper-level trough located well to its north. The HFIP Corrected Consensus (HCCA) and Google DeepMind ensemble (GDMI) are the fastest and farthest south models. The latest NHC forecast track is nearly identical to the previous forecast for the first 72 hours, and then is slightly to the left of the previous track at days 4-5. The latest NHC forecast lies in between the TVCN simple consensus, which is a bit slower and to the right, and the HCCA, which is faster and to the left. SHIPS and UW-CIMSS vertical wind shear analyses indicate that the easterly wind shear is starting to decrease, and is likely around 10 kt now. Satellite imagery suggests that it may take a little more time for the core of Lowell to be ready to begin intensifying more quickly. The HAFS models, as well as the HWRF and HMON all forecast the cyclone to become a major hurricane over the next 2 days, so no significant change has been made to the NHC intensity forecast. The shear is expected to be weak throughout the next 5 days and water temperatures will remain warm along Lowell's path, so the forecast calls for Lowell to maintain its strength through day 5 as a major hurricane. The intensity forecast remains between the middle and higher end of the intensity guidance envelope. Key Messages: 1. Lowell is forecast to move generally westward and could be in the vicinity of the Hawaiian Islands late this week or this weekend. Interests in Hawaii should monitor the progress of this storm. FORECAST POSITIONS AND MAX WINDS INIT 31/2100Z 12.9N 146.5W 55 KT 65 MPH 12H 01/0600Z 13.0N 147.9W 65 KT 75 MPH 24H 01/1800Z 13.3N 149.7W 80 KT 90 MPH 36H 02/0600Z 13.5N 151.6W 95 KT 110 MPH 48H 02/1800Z 13.7N 153.5W 105 KT 120 MPH 60H 03/0600Z 14.1N 155.4W 105 KT 120 MPH 72H 03/1800Z 14.4N 157.3W 105 KT 120 MPH 96H 04/1800Z 14.9N 160.2W 105 KT 120 MPH 120H 05/1800Z 15.3N 162.5W 105 KT 120 MPH