Tropical Storm Lowell Forecast Discussion
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000 WTPA44 PHFO 102044 TCDCP4 Tropical Storm Lowell Discussion Number 59 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 1100 AM HST Thu Sep 10 2026 Infrared satellite imagery over the last couple of hours depicts Lowell's convection concentrated over a small area within its northeastern quadrant. The system also appears heavily sheared, with Lowell's low-level center exposed and displaced from the convection. Subjective Dvorak intensity estimates from HFO and JTWC provided Lowell with a final T-number of 1.5 and 2.0, respectively, which would put the intensity at around 25-30 kt. However, given the earlier higher scatterometer winds, and some lingering convection currently, the initial intensity was only lowered slightly to 45 kt. The initial motion was estimated at 270/10 kt. Lowell continues to be steered by a mid-level high pressure system centered to the northeast, with a cutoff low based in the north central Pacific expected to dive down and turn the system to the northwest heading into the weekend. Lowell's forward motion is then expected to decrease over the weekend as it finds itself wedged between two low- to mid-level ridges. Track models continue to exhibit a wide spread beyond 36 h, differing in both how the cutoff low alters Lowell's track and how slow the storm motion becomes once it's centered between the ridges. The official track forecast was little changed across the first 36 h, with the main changes beyond that period. Guidance generally pulls Lowell a little more northwestward toward the cutoff low before drifting southward at a slow motion as Lowell becomes more vertically shallow. This turn to the south was made slightly wider to reflect the global model consensus. Lowell remain in a hostile environment characterized by moderate vertical wind shear, dry mid-level air, and marginal SSTs. Despite this environment, intensity guidance depicts a slight increase in max winds around early Saturday morning, suggesting that the cutoff low may briefly enhance Lowell's convection. Simulated satellite imagery from the GFS and ECMWF, however, suggest that Lowell's convection may wither before then, with post-tropical transition potentially occurring before this interaction takes place. The latest intensity forecast holds Lowell's intensity relatively steady for the first day or so, before showing a brief increase in intensity at 48 h. Thereafter, gradual weakening is expected to occur through early next week. The forecast has Lowell becoming post-tropical in 60 h, a little earlier than the previous forecast, though it remains possible this could occur even sooner than shown here. 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. FORECAST POSITIONS AND MAX WINDS INIT 10/2100Z 29.0N 168.9W 45 KT 50 MPH 12H 11/0600Z 29.0N 170.4W 40 KT 45 MPH 24H 11/1800Z 29.6N 171.7W 40 KT 45 MPH 36H 12/0600Z 31.2N 172.2W 40 KT 45 MPH 48H 12/1800Z 32.8N 173.0W 45 KT 50 MPH 60H 13/0600Z 33.9N 174.0W 35 KT 40 MPH...POST-TROPICAL 72H 13/1800Z 33.8N 175.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 14/1800Z 32.9N 175.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 15/1800Z 31.0N 175.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Evans/Papin