Tropical Cyclone Discussion
103 WTPA44 PHFO 060235 TCDCP4 Hurricane Lowell Discussion Number 40 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 500 PM HST Sat Sep 05 2026 Lowell remains an impressive and well-organized major hurricane this afternoon, although satellite imagery suggests that some weakening has occurred during the past several hours. The eye remains well defined and is surrounded by a largely symmetric eyewall, but visible and infrared imagery show some erosion of the convection within the northeastern portion of the eyewall, where cloud-top temperatures have warmed. This could be the result of some mid-level dry air becoming entrained into the inner core. Although an eyewall replacement cycle cannot be ruled out, there are still no recent microwave data to indicate that a secondary eyewall has formed. Subjective Dvorak Current Intensity estimates from HFO and JTWC are both 6.0, corresponding to 115 kt, while objective intensity estimates range from about 105 to 125 kt. Based on a blend of these data and the modest degradation of the satellite presentation, the initial intensity is lowered to 115 kt for this advisory. A NOAA G-IV aircraft is currently sampling the environment surrounding Lowell, and these data should be incorporated into upcoming model cycles. Lowell has continued to slowly gain latitude, with an initial motion of 300/4 kt. A cutoff upper-level low north-northeast of the Hawaiian Islands is forecast to move 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 track guidance remains in good agreement and continues to show the center of Lowell passing west of Kauai County late Monday into early Tuesday. The latest NHC track forecast is essentially an update of the previous advisory and brings the center of Lowell about 150 to 175 n mi west of Niihau around the time of closest approach. After passing the main Hawaiian Islands, Lowell is forecast to turn west-northwestward and slow as weak ridging builds to the north of the cyclone. Some fluctuations in intensity remain possible through early Sunday due to internal structural changes. However, the overall trend is expected to be toward gradual weakening. Deep-layer vertical wind shear is forecast to increase substantially beginning Sunday as Lowell turns northward and accelerates toward the vicinity of the western main Hawaiian Islands. Increasingly dry mid-level air should also become entrained into the circulation during this time. These increasingly hostile environmental conditions should cause the rate of weakening to increase Sunday night and Monday. Despite the expected weakening, Lowell is forecast to remain a major hurricane when it makes its closest approach to Kauai County and passes across portions of the Papahanaumokuakea Marine National Monument. Thereafter, a combination of strong vertical wind shear and drier air should result in continued weakening. The latest NHC intensity forecast is essentially an update of the previous advisory. KEY MESSAGES: 1. Lowell is forecast to pass west of Kauai County late Monday into early Tuesday. A Tropical Storm Watch has been issued for Kauai County, including Kauai and Niihau, where tropical storm conditions are possible beginning Monday. A Hurricane Watch has been issued for portions of the Papahanaumokuakea Marine National Monument from Nihoa to French Frigate Shoals. 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 late Monday into Monday night. FORECAST POSITIONS AND MAX WINDS INIT 06/0300Z 13.7N 163.4W 115 KT 130 MPH 12H 06/1200Z 14.4N 163.8W 115 KT 130 MPH 24H 07/0000Z 15.5N 164.0W 110 KT 125 MPH 36H 07/1200Z 17.2N 163.6W 105 KT 120 MPH 48H 08/0000Z 19.7N 162.9W 100 KT 115 MPH 60H 08/1200Z 22.7N 162.3W 95 KT 110 MPH 72H 09/0000Z 25.0N 162.7W 85 KT 100 MPH 96H 10/0000Z 26.8N 164.9W 60 KT 70 MPH 120H 11/0000Z 27.3N 168.6W 45 KT 50 MPH