Tropical Cyclone Discussion
091 WTPA44 PHFO 052043 TCDCP4 Hurricane Lowell Discussion Number 39 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 1100 AM HST Sat Sep 05 2026 Lowell's satellite presentation has degraded further this morning with what appears to be a moat developing around the eyewall in visible and satellite imagery. This could suggest that Lowell is beginning to go through an eyewall replacement, but the most recent microwave data did not show signs of a secondary eyewall. It's also possible that the hurricane has ingested dry air that is eroding some of the convection outside of the inner core. Either way, subjective Dvorak Current Intensity numbers and objective estimates now support an initial intensity of 125 kt. Lowell appears to have begun its expected turn, with the initial motion now west-northwestward (285/6 kt). A deep-layer low located about 500 n mi north-northeast of the Hawaiian Islands is forecast to dip southwestward over the next couple of days, which will cause Lowell to make a sharp northward to north-northeastward turn, accompanied by an increase in forward speed, by Sunday and Monday. The track guidance has not changed much since the last cycle and remains in good agreement that Lowell's center will move 100-200 n mi to the west of Kauai County in 60-72 hours. Since the models didn't change much, the new NHC track forecast is very similar to the previous forecast. After passing the main Hawaiian Islands after day 3, Lowell is forecast to turn toward the west-northwest and slow down as weak ridging again builds in north of the cyclone. The official intensity forecast shows a steady intensity for the next 12 hours or so, leaving the door open for possible fluctuations in intensity, especially if an eyewall replacement does occur. Overall, however, models suggest that gradual weakening will continue, especially once deep-layer shear increases in 36-48 hours. The updated NHC intensity forecast has again been lowered slightly from the previous prediction to follow model trends, but it still shows Lowell being near or at major hurricane strength when it makes its closest approach to the western main Hawaiian Islands and passes across portions of the Papahanaumokuakea Marine National Monument. After day 3, the addition of cooler waters and drier air should cause Lowell to weaken to a tropical storm by day 4. KEY MESSAGES: 1. Lowell is forecast to move close to the western Hawaiian Islands late Monday and Monday night. There is a risk of wind and coastal flooding impacts for Kauai County at that time, and a tropical storm watch will likely be issued later today. Residents and tourists should follow advice from local officials. 2. Heavy rainfall associated with Lowell will begin to impact the Hawaiian Islands Sunday afternoon and continue through early next week. Periods of heavy rain may produce locally significant flash flooding and mudslides, especially in areas of steep terrain. 3. Swells from Lowell are likely to cause life-threatening surf and rip current conditions in portions of the Hawaiian Islands during the next several days. These swells are likely to increase early next week. FORECAST POSITIONS AND MAX WINDS INIT 05/2100Z 13.5N 163.1W 125 KT 145 MPH 12H 06/0600Z 13.9N 163.7W 125 KT 145 MPH 24H 06/1800Z 14.9N 164.2W 120 KT 140 MPH 36H 07/0600Z 16.2N 164.1W 115 KT 130 MPH 48H 07/1800Z 18.2N 163.4W 110 KT 125 MPH 60H 08/0600Z 21.1N 162.7W 105 KT 120 MPH 72H 08/1800Z 23.9N 162.4W 90 KT 105 MPH 96H 09/1800Z 26.9N 163.9W 60 KT 70 MPH 120H 10/1800Z 27.6N 167.5W 45 KT 50 MPH