Tropical Cyclone Discussion
289 WTPA44 PHFO 090851 TCDCP4 Tropical Storm Lowell Discussion Number 53 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 1100 PM HST Tue Sep 08 2026 Proxy-visible satellite and water vapor imagery show that Lowell has continued to deteriorate as the cyclone has been adversely affected by dry air and wind shear. The center of the cyclone has moved underneath an area of deep convection that has formed recently, however the bulk of the convection is on the northern side of the circulation. Recent subjective Dvorak intensity estimates are 45-55 kt, while the objective intensity estimates are lower in the range of 41-46 kt. Since earlier scatterometer data showed stronger winds than suggested by the satellite estimates, the initial intensity is only lowered to 55 kt for this advisory. Lowell is currently moving northward around 12 kt, as the storm is being guided by a mid-level low to the northwest and a ridge from the north-northeast. On Wednesday, a more gradual shift towards the northwest should occur as high pressure builds in from the north. The storm is then expected to lose speed on Thursday as the cyclone becomes more shallow and lower-level flow becomes more dominant. There is a good degree of uncertainty in the track around 72 h, as Lowell approaches another upper-level low from the northwest. The guidance generally has the cyclone turning to the north or north-northwest around Friday and into the weekend. There is a large spread in the guidance about the timing and how far north the storm will go. Given the spread in the track models, there is a higher than normal uncertainty in the long-range NHC track forecast. This forecast is similar to the previous prediction, but nudged to the right based on the latest consensus aids. Lowell is expected to remain in a hostile environment with moderate wind shear and dry air, thus a gradual weakening trend is expected to occur. The simulated satellite imagery from the GFS and ECMWF indicate that Lowell could lose most of its deep convection by Thursday, and potentially become a post-tropical cyclone on Friday. However, the previously mentioned second upper-level low could help Lowell build some deep convection late Friday into Saturday. This in turn could cause some slight strengthening of the storm, but there is uncertainty regarding the stucture of Lowell at that time. Therefore, there is a good degree of uncertainty with this portion of the intensity forecast. The current NHC intensity forecast is similar to the previous prediction and calls for Lowell to become a post-tropical remnant low around day 5. KEY MESSAGES: 1. Post-storm safety: Follow advice of local officials and avoid areas of downed power lines and flooding. Ensure generators are properly ventilated and placed outside at least 20 feet away from dwellings and garages to avoid carbon monoxide poisoning. During clean up, be careful when using chainsaws and power tools. Drink plenty of water to avoid heat exhaustion. 2. Large waves will continue to produce life-threatening surf and rip current conditions during the next day or so along exposed coasts of the Hawaiian Islands. FORECAST POSITIONS AND MAX WINDS INIT 09/0900Z 27.3N 161.5W 55 KT 65 MPH 12H 09/1800Z 28.4N 162.7W 50 KT 60 MPH 24H 10/0600Z 29.0N 165.4W 50 KT 60 MPH 36H 10/1800Z 28.8N 167.7W 45 KT 50 MPH 48H 11/0600Z 28.7N 169.8W 40 KT 45 MPH 60H 11/1800Z 29.1N 171.2W 40 KT 45 MPH 72H 12/0600Z 30.3N 171.7W 40 KT 45 MPH 96H 13/0600Z 32.6N 173.1W 35 KT 40 MPH 120H 14/0600Z 33.6N 174.8W 30 KT 35 MPH...POST-TROPICAL