Tropical Cyclone Discussion
196 WTPA44 PHFO 070244 TCDCP4 Hurricane Lowell Discussion Number 44 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 500 PM HST Sun Sep 06 2026 Before departing Lowell, the final fix from the Air Force Reserve Hurricane Hunter mission found the hurricane was mostly steady state, with peak flight level winds of 109 kt and a minimum pressure still at 948 mb. While a closed 30 n mi wide eye remains, there was evidence of a secondary wind maximum beginning to form on the recon flight, and a secondary convective ring can also be seen from a recent AMSR3 microwave image, suggesting another eyewall replacement cycle may soon be underway. While the aircraft flight level winds support a maximum sustained wind of around 100 kt, the eastern side of Lowell was not fully sampled where the highest winds might be present given the current motion. This assessment, combined with higher satellite intensity estimates suggests maintaining the intensity at 105 kt this advisory. Lowell is now moving a little east of due north this afternoon, estimated at 010 degrees at 8 kt. The synoptic situation continues to evolve as a cutoff mid- to upper-level low sliding west-southwest is beginning to capture Lowell, as mid-level ridging to the hurricane's southeast should generally impart a northward to north-northeastward motion over it for the next 24-48 h as Lowell gradually accelerates. Like this afternoon, there has been another eastward shift in the guidance, with the HFIP Corrected Consensus Approach (HCCA) and Google DeepMind (GDMI) aids along with the HAFS hurricane-regional models on the eastern side of the guidance envelope. Thus, the NHC official forecast has been shifted a little more eastward in response to these model trends. After 48 h, the cutoff low influencing Lowell's motion is forecast to lift out, with a mid-level ridge building back in to the north, which should result in the cyclone turning back to the northwest or even west in the latter half of the forecast period. While vertical wind shear over Lowell is currently low, it is soon forecast to increase out of the southwest to above 30 kt in 24 h. This shear, combined with the likelihood that Lowell may soon undergo another eyewall replacement cycle will likely lead to weakening, first slowly, and then a faster rate in the 24-48 h time frame. This solution is reflected in the latest NHC intensity forecast, which shows slow weakening tonight, but a faster rate of weakening by Monday night into Tuesday when the shear is expected to be 30-40 kt over the hurricane. Regardless, Lowell is still forecast to be a hurricane when it makes it closest point of approach to the Hawaii Islands on Monday night. After passing by, Lowell should continue to weaken below hurricane intensity, and there remain some possibility of the storm becoming post-tropical by the end of the forecast period, though significant uncertainty remain in the model guidance by the 120 h period. Given the eastward shift in the track guidance and with the expectation that Lowell's radii will also be larger on its eastern semicircle, the risk of hurricane conditions for Kauai and Niihau has increased, and a Hurricane Watch has now been issued for this portion of the Hawaiian Islands. KEY MESSAGES: 1. Lowell's center is forecast to pass just west of Kauai County late Monday into early Tuesday. A Hurricane Watch and Tropical Storm Warning is now in effect for Kauai County, including Kauai and Niihau, where hurricane conditions are possible and tropical storm conditions are expected to begin Monday afternoon and continue through Tuesday morning. Wind gusts to hurricane force are also possible atop mountains and on windward and leeward slopes. 2. Periods of heavy rainfall associated with Hurricane Lowell will increase in coverage over the Hawaiian Islands tonight and continue through Wednesday. This may produce significant flash flooding and mudslides, especially across Kauai county 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 produce coastal flooding and inundation of low-lying areas Monday through Monday night. FORECAST POSITIONS AND MAX WINDS INIT 07/0300Z 15.9N 163.5W 105 KT 120 MPH 12H 07/1200Z 17.2N 163.0W 100 KT 115 MPH 24H 08/0000Z 19.7N 162.1W 95 KT 110 MPH 36H 08/1200Z 22.6N 161.5W 80 KT 90 MPH 48H 09/0000Z 25.3N 161.5W 65 KT 75 MPH 60H 09/1200Z 27.0N 162.0W 55 KT 65 MPH 72H 10/0000Z 27.8N 164.0W 50 KT 60 MPH 96H 11/0000Z 27.8N 168.4W 45 KT 50 MPH 120H 12/0000Z 28.0N 170.9W 35 KT 40 MPH