Tropical Cyclone Discussion
Issued by NWS
Issued by NWS
047 WTPA44 PHFO 090241 TCDCP4 Tropical Storm Lowell Discussion Number 52 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 500 PM HST Tue Sep 08 2026 The structure of Lowell continues to deteriorate this afternoon as dry mid-level air and wind shear affect the tropical storm. The low-level center of circulation is now almost completely exposed, with deep convection displaced well to the north. In addition, a strong mid-level low is interacting with Lowell and is contributing to southwesterly to westerly wind shear across the system. Recent subjective Dvorak intensity estimates range from 55 to 65 kt, while objective estimates are somewhat lower, generally between 46 and 50 kt. The initial intensity is set at 60 kt for this advisory. An earlier scatterometer pass also provided valuable guidance in refining Lowell`s wind radii. Lowell is moving northward around 13 kt, steered primarily by the aforementioned mid-level low to the northwest and ridging to the north-northeast. A gradual turn toward the northwest is expected tonight through Wednesday as the low interacts with Lowell and high pressure builds to the north. The storm is forecast to slow down on Thursday as Lowell becomes increasingly shallow and begins to move more in response to the low-level flow. The track forecast becomes considerably more complex beyond 72 h as Lowell encounters another elongated upper-low approaching from the northwest. Most model guidance indicates that Lowell should turn toward the north or northwest late this week into this weekend, but there is considerable spread in the guidance regarding both the timing of this turn and how far north the cyclone will ultimately track. The latest NHC forecast remains on the southern side of the guidance envelope and is close to the previous track, with the forecast lying closest to HCCA and the Google DeepMind solutions. Moderate wind shear and unfavorable upper-level winds will continue to support gradual weakening of Lowell over the next several days. Simulated satellite imagery from the GFS and ECMWF suggest that Lowell could struggle to maintain organized deep convection by Thursday, potentially bringing the cyclone closer to becoming post-tropical on Friday. However, the second elongated upper-level low pressure system may help reinvigorate convection late Friday into Saturday, which could provide an opportunity for slight strengthening during that time. The latest NHC intensity forecast is very close to the previous advisory and calls for Lowell to become a post-tropical remnant low around day 5. Confidence in the longer-range track and intensity forecast is lower than average. 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. The threat of locally moderate to heavy rainfall associated with Lowell will linger over parts of the eastern Hawaiian Islands into Wednesday. This may result in additional flooding of urban and low-lying portions of the Big Island and may promote instances of new flooding or prolong any ongoing flooding elsewhere across the Islands. 3. 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 09/0300Z 26.2N 161.1W 60 KT 70 MPH 12H 09/1200Z 27.7N 162.0W 50 KT 60 MPH 24H 10/0000Z 28.7N 164.1W 50 KT 60 MPH 36H 10/1200Z 28.8N 166.7W 45 KT 50 MPH 48H 11/0000Z 28.5N 169.1W 40 KT 45 MPH 60H 11/1200Z 28.5N 170.9W 35 KT 40 MPH 72H 12/0000Z 29.1N 171.9W 40 KT 45 MPH 96H 13/0000Z 31.8N 172.9W 40 KT 45 MPH 120H 14/0000Z 32.9N 175.2W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Adams