Tropical Cyclone Discussion
287 WTPA44 PHFO 042039 TCDCP4 Hurricane Lowell Discussion Number 35 NWS Central Pacific Hurricane Center Honolulu HI EP122026 Issued by NWS National Hurricane Center Miami FL 1100 AM HST Fri Sep 04 2026 Lowell has strengthened rapidly this morning. The eye of the hurricane has become larger and more distinct with multiple mesovortices evident in satellite images. In fact, the eye temperature has increased significantly to around 20 C. In addition, the convection in the eyewall is now notably more symmetric than it was earlier. Data from the Air Force Hurricane Hunters indicate that Lowell is a powerful category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale, with peak winds around 130 kt. Dropsonde data suggests that the minimum pressure is around 926 mb. The initial wind radii has been expanded in all quadrants based on the aircraft data. Lowell continues to lose some latitude this morning, with the initial motion estimated to be 255/6 kt. A general westward motion is expected through Saturday as the hurricane remains steered by the flow on the southeastern side of a mid-level ridge. On Sunday, the steering pattern is expected to change when a mid- to upper-level low moves southwestward to the north of the Hawaiian Islands, eroding the southern portion of the ridge. This pattern change should cause a sharp turn to the north or north-northeast with a gradual increase in forward speed, bringing the system close to the westernmost Hawaiian Islands on Monday and Monday night. It should be noted that predicting where and how sharply Lowell turns is challenging as it will depend on the location and amplitude of the mid- to upper-level low relative to the hurricane's location. Overall, the guidance has not changed much this cycle, and the NHC official track forecast is very similar to the previous one. This prediction is in good agreement with the Google DeepMind ensemble mean and simple consensus TVCN. Lowell's rapid intensification episode could continue a little longer since the hurricane has been maintaining a symmetric inner core while remaining in conducive environmental conditions. Lowell could regain category 5 intensity later today or tonight if this intensification trend continues. However, a pronounced increase in southerly or southwesterly vertical wind shear and progressively cooler waters should promote a steady weakening trend beginning in a couple of days. Although there is good confidence that Lowell will be weakening when it nears the westernmost Hawaiian Islands, it will very likely still be at or close to major hurricane strength. The NHC intensity forecast is higher than the previous one and above the model guidance in the short term. However, it is fairly similar to the past few advisories from 72 to 120 h. KEY MESSAGES: 1. Lowell is forecast to be near major hurricane strength when it moves close to the western Hawaiian Islands late Monday and Monday night. There is a risk of storm surge and wind impacts for portions of Hawaii, particularly Kauai County, early next week and watches will likely be issued on Saturday. Residents should ensure they have their hurricane plan in place and follow advice from local officials. 2. Heavy rainfall will begin to impact the Hawaiian Islands Sunday afternoon and continue through early next week. This rainfall could produce 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 04/2100Z 13.2N 160.7W 130 KT 150 MPH 12H 05/0600Z 13.2N 161.7W 145 KT 165 MPH 24H 05/1800Z 13.5N 162.8W 145 KT 165 MPH 36H 06/0600Z 14.0N 163.6W 140 KT 160 MPH 48H 06/1800Z 15.0N 164.0W 135 KT 155 MPH 60H 07/0600Z 16.3N 163.9W 125 KT 145 MPH 72H 07/1800Z 18.4N 163.3W 115 KT 130 MPH 96H 08/1800Z 23.6N 162.5W 95 KT 110 MPH 120H 09/1800Z 27.0N 163.8W 75 KT 85 MPH