Tropical Cyclone Discussion
904 WTPA44 PHFO 060857 TCDCP4 Hurricane Lowell Discussion Number 41 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 1100 PM HST Sat Sep 05 2026 Lowell remains an impressive hurricane, with a warm and well-defined eye surrounded by a generally symmetric eyewall. However, infrared imagery shows some warming of the cloud tops within portions of the eyewall. Recent microwave imagery also shows some hints of an outer eyewall-like feature, although it currently appears more like a convective band and is not sufficiently organized to confirm that an eyewall replacement cycle is beginning. Subjective Dvorak Current Intensity estimates range from 5.5 from JTWC to 6.0 from HFO, corresponding to 102 to 115 kt, while objective intensity estimates generally range from 100 to 120 kt. Based on a blend of these estimates and the gradual weakening trend, the initial intensity is lowered to 110 kt for this advisory, making Lowell a Category 3 hurricane. Lowell continues to gain latitude and has begun to make its anticipated turn, with an initial motion of 325/4 kt. A cutoff upper low north of the Hawaiian Islands will continue southwestward during the next couple of days. As Lowell becomes increasingly influenced by this feature, the hurricane should turn northward on Sunday and then north-northeastward while accelerating Sunday night and Monday. The latest track guidance has shifted slightly eastward, but remains in generally good agreement on the overall evolution of Lowell's motion. The NHC track forecast has also been shifted slightly eastward and represents a blend of the previous forecast, the simple and multi-model consensus aids TVCN and HCCA, and the Google DeepMind ensemble mean. After passing west of the main Hawaiian Islands, Lowell is forecast to turn toward the west-northwest and slow as weak ridging builds to the north of the cyclone. Some fluctuations in intensity remain possible in the short term due to potential inner-core structural changes. However, the overall trend is expected to be toward continued weakening. The environment should remain generally favorable through early Sunday, but deep-layer vertical wind shear is forecast to increase markedly during the 24- to 48-h period as Lowell turns northward and then north-northeastward and accelerates. Increasing dry mid-level air should also become entrained into the circulation during this time. These hostile environmental conditions are expected to result in a faster rate of weakening by Monday night and Tuesday. Despite the expected weakening, Lowell is forecast to remain a powerful hurricane when it passes west of Kauai County Monday night and across portions of the Papahanaumokuakea Marine National Monument. Thereafter, strong vertical wind shear, drier air, and progressively cooler waters should result in continued weakening. The NHC intensity forecast is similar to the previous advisory and generally lies within the middle to upper end of the intensity guidance envelope. KEY MESSAGES: 1. Lowell is forecast to pass west of Kauai County late Monday into early Tuesday. A Tropical Storm Watch remains in effect for Kauai County, including Kauai and Niihau, where tropical storm conditions are possible beginning Monday. A Hurricane Watch is in effect for portions of the Papahanaumokuakea Marine National Monument from Nihoa to French Frigate Shoals, where hurricane conditions are possible beginning Monday. 2. Heavy rainfall associated with Hurricane Lowell will begin to impact the Hawaiian Islands Sunday afternoon and continue through early next week. Periods of heavy rain may produce significant flash flooding and mudslides, especially on Kauai and portions of the Big Island. 3. Large swells from Lowell are expected to produce life-threatening surf and rip current conditions across portions of the Hawaiian Islands during the next several days. Surf along exposed portions of Kauai County could also produce coastal flooding and inundation of low-lying areas Monday through Monday night. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 14.1N 163.5W 110 KT 125 MPH 12H 06/1800Z 14.8N 163.8W 110 KT 125 MPH 24H 07/0600Z 16.3N 163.8W 110 KT 125 MPH 36H 07/1800Z 18.5N 163.1W 105 KT 120 MPH 48H 08/0600Z 21.4N 162.4W 95 KT 110 MPH 60H 08/1800Z 24.1N 162.2W 85 KT 100 MPH 72H 09/0600Z 25.7N 162.9W 75 KT 85 MPH 96H 10/0600Z 27.2N 165.6W 60 KT 70 MPH 120H 11/0600Z 27.5N 170.0W 45 KT 50 MPH