{"id": "1212687003709767687", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-23T09:00:00Z", "msg": "360\nWTPA42 PHFO 230844\nTCDCP2\n \nTropical Depression Fifteen-E Discussion Number  11\nNWS Central Pacific Hurricane Center Honolulu HI   EP152026\nIssued by NWS National Hurricane Center Miami FL\n1100 PM HST Tue Sep 22 2026\n \nRecent satellite imagery indicates that the low-level circulation \nassociated with the remnants of former Tropical Depression Fifteen-E \nhas once again become well-defined as the system crossed from the \nwestern East Pacific basin into the central Pacific basin. There has \nbeen persistent deep convection, mainly in a band to the north and \nwest of the low-level center. Since the remnants have maintained \ntrackable with continuity for over a week since losing its tropical \ncyclone status, advisories are being re-initiated and the system \nwill retain its original designation as Tropical Depression \nFifteen-E. The initial intensity is set at 30 kt and is based on the \nlatest objective intensity estimates from UW-CIMSS. It is worth \nnoting that if the cyclone becomes a tropical storm, it will receive \nthe Central Pacific name Nolo.\n\nThe depression is moving west-northwestward at about 10 kt on the \nsouthwest side of a low- to mid-level ridge. This ridge is expected \nto shift eastward and weaken while a mid- to upper-level low dives \nsouthwestward near the northwestern Hawaiian Islands. This pattern \nchange should cause the cyclone to slow down and then turn northward \nor north-northeastward later this week. That motion should take the \ncyclone near the Big Island of Hawaii late Friday or on Saturday.  \nAround that time, the upper low is expected to weaken and move \nwestward, allowing mid-level ridging to become re-established to the \nnorth of the system. In response, the cyclone should turn and then \naccelerate westward. The NHC track forecast is closest to the \nbest-performing models of the year so far, HCCA and GDMI. Given the \ncomplex steering evolution and significant model spread, confidence \nin the details of the track forecast is low. Interests in the \nHawaiian Islands, especially on the Big Island, should closely \nmonitor the system. \n\nThe environmental conditions are favorable for strengthening over \nthe next few days with vertical wind shear expected to be around or \nless than 10 kt, high mid-level humidities, and SSTs of around 29 \nC. The only limiting factor is the system's sprawling low-level \nstructure. Considering these conditions, the NHC intensity forecast \ncalls for slow strengthening to start, followed by more significant \nintensification when the system moves toward Hawaii. Most of the \nreliable intensity models are quite aggressive, and the NHC \nintensity forecast follows a combination of the HAFS guidance and \nHCCA and GDMI aids. This prediction shows the system becoming a \nhurricane in a couple of days and nearing major hurricane strength \nwhen it approaches the Big Island of Hawaii by the weekend.\n \nKey Messages:\n \n1. Tropical Depression Fifteen-E is expected to strengthen into a\ntropical storm on Wednesday and a hurricane in a couple of days as\nit turns northward. Although it is too soon to specify the exact\nlocation and magnitude of impacts, interests in Hawaii should\nclosely monitor the latest forecast updates and ensure that they\nhave their preparedness plan in place.\n \n2. Heavy rainfall associated with Tropical Depression Fifteen-E will \nbegin to affect the eastern portions of Hawaii Wednesday. Periods of \nheavy rain are likely to continue across the Big Island and Maui \nthrough Saturday. Life-threatening, catastrophic flooding and \nmudslides are possible from rainfall totals in excess of a foot, \nespecially in areas of steep terrain. Across the remainder of \nHawaii, lesser rainfall totals are expected, with isolated flooding \npossible. \n \n3. There is an increasing risk of wind and wave impacts in the\nHawaiian Islands regardless of the exact track and intensity of the\nsystem. Hurricane or Tropical Storm Watches may be required for\nportions of the Hawaiian Islands on Wednesday.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  23/0900Z 14.0N 153.7W   30 KT  35 MPH\n 12H  23/1800Z 14.4N 154.7W   35 KT  40 MPH\n 24H  24/0600Z 14.6N 155.5W   45 KT  50 MPH\n 36H  24/1800Z 15.0N 155.6W   55 KT  65 MPH\n 48H  25/0600Z 15.9N 155.2W   70 KT  80 MPH\n 60H  25/1800Z 17.0N 154.9W   85 KT 100 MPH\n 72H  26/0600Z 17.9N 154.7W   95 KT 110 MPH\n 96H  27/0600Z 18.3N 156.0W   95 KT 110 MPH\n120H  28/0600Z 18.2N 159.0W   95 KT 110 MPH\n \n"}