Tropical Cyclone Discussion
003 WTPA42 PHFO 140836 TCDCP2 Tropical Storm Lala Discussion Number 8 NWS Central Pacific Hurricane Center Honolulu HI CP012026 Issued by NWS National Hurricane Center Miami FL 1100 PM HST Thu Aug 13 2026 Lala has shown little change in organization over the past several hours. Most of the deep convection remains confined to the northern portion of the circulation, with little deep convection occurring south of the center. Air Force Reserve Hurricane Hunter aircraft investigating Lala has measured peak 850-mb flight-level winds of 55 kt. In addition, 0621 UTC METOP-B and 0645 UTC METOP-C scatterometer passes provided useful information for adjusting the tropical-storm-force wind radii and confirmed the highly asymmetric nature of the circulation, with much weaker winds across the southern semicircle. Based on all of the available data, the initial intensity is held at a generous 50 kt for this advisory. The initial motion estimate is west-northwestward, or 290/9 kt. The overall track forecast philosophy remains largely unchanged. A strong mid-level ridge north of the Hawaiian Islands should continue to steer the cyclone west-northwestward during the next several days. The cyclone's forward motion is forecast to slow somewhat as it approaches and begins to interact with the terrain of the Big Island on Saturday. Some short-term deviations in the track are also possible during this time due to these terrain interactions. Lala should then resume a faster west-northwestward motion as it passes south of the smaller islands through the remainder of the weekend, and south of the Northwestern Hawaiian Islands Sunday night into early next week. The latest NHC track forecast is very similar to the previous advisory and remains close to the multi-model consensus (HCCA) and Google DeepMind ensemble mean. Environmental conditions are expected to remain generally favorable for strengthening during the next couple of days, with the primary limiting factor being the dry mid-level air that continues to be entrained into the cyclone's large circulation. Steady strengthening is forecast, and Lala is expected to become a hurricane as it approaches the Big Island on Saturday. Interaction with the terrain of the Big Island could result in short-term changes in the cyclone's structure and intensity during its closest approach. Thereafter, a progressively drier mid-level environment, along with some increase in westerly vertical wind shear, should result in weakening as Lala passes south of the smaller islands through the remainder of the weekend. Some re-strengthening is forecast early next week as vertical wind shear relaxes and Lala remains over warm sea surface temperatures. The latest NHC intensity forecast is similar to the previous advisory and remains near the middle to upper end of the guidance envelope. Key Messages: 1. Lala is forecast to strengthen and become a hurricane as it approaches the Big Island of Hawaii by early Saturday. A Hurricane Warning remains in effect for the Big Island and a Tropical Storm Watch is in effect for Maui County. Winds are expected to be the strongest in areas of higher terrain. 2. Heavy rainfall associated with Tropical Storm Lala will begin to impact the Big Island Friday, spreading westward across the remainder of the island chain during the weekend. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. 3. Large and dangerous waves, especially on the Big Island, are expected this weekend, with the greatest impacts along exposed windward and southern shores. This prolonged period of heavy surf may cause localized coastal flooding and significant beach erosion. 4. Interests elsewhere in Hawaii should monitor the progress of Lala, and Tropical Storm Watches or Warnings could be required on Friday. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 16.7N 148.9W 50 KT 60 MPH 12H 14/1800Z 16.9N 150.0W 55 KT 65 MPH 24H 15/0600Z 17.6N 152.2W 60 KT 70 MPH 36H 15/1800Z 18.3N 154.1W 65 KT 75 MPH 48H 16/0600Z 19.2N 156.5W 65 KT 75 MPH 60H 16/1800Z 20.1N 159.4W 60 KT 70 MPH 72H 17/0600Z 20.7N 162.0W 60 KT 70 MPH 96H 18/0600Z 21.4N 166.5W 65 KT 75 MPH 120H 19/0600Z 22.5N 170.5W 70 KT 80 MPH