{"id": "1212969759121539079", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-24T09:00:00Z", "msg": "602\nWTPA42 PHFO 240843\nTCDCP2\n \nTropical Storm Nolo Discussion Number  15\nNWS Central Pacific Hurricane Center Honolulu HI   EP152026\nIssued by NWS National Hurricane Center Miami FL\n1100 PM HST Wed Sep 23 2026\n \nNolo's convective organization has gradually improved during the \npast several hours, with a curved band of persistent deep convection \ntightening around the circulation center. The latest subjective \nDvorak intensity estimates from JTWC and HFO are both T2.5/35 kt, \nwhile objective intensity estimates range from 35 to 55 kt. Given \nthe improved convective organization and the higher objective \nestimates, the initial intensity is raised to 45 kt.\n \nNolo has slowed considerably and appears to be making its \nanticipated northward turn, with an initial motion of 360/2 kt. A \nweakening subtropical ridge northeast of Hawaii should allow Nolo to \ncontinue moving slowly northward into Thursday, followed by a \nnorth-northeastward motion as an upper-level trough deepens \nnorthwest of the Hawaiian Islands. As the trough shifts westward and \nthe subtropical ridge rebuilds north of the cyclone, Nolo is \nforecast to make a sharp westward turn Friday night into Saturday. \nThe latest GDMI and HCCA guidance has shifted slightly northward, \nbringing the system closer to the Big Island. Given the run-to-run \ninconsistencies in the guidance, the NHC track forecast is \nessentially an update of the previous advisory and shows Nolo \npassing south of the Big Island on Saturday before continuing \nwestward south of the smaller Hawaiian Islands through the latter \nportion of the weekend. However, considerable uncertainty remains \nregarding the influence of the deepening upper-level trough on \nNolo's track, as well as the timing and strength of the subtropical \nridge rebuilding north of the cyclone. Even relatively small \ndifferences in the evolution of these steering features could \nsignificantly alter the timing and location of Nolo's sharp westward \nturn and, ultimately, how close its center passes to the Big Island. \nA track closer to the Big Island could also result in interactions \nwith the island's terrain that could further influence the cyclone's \nsubsequent motion. Given these uncertainties, confidence in the \ntrack forecast remains lower than normal.\n \nEnvironmental conditions remain favorable for strengthening, with\nvery warm sea surface temperatures and plenty of mid-level moisture\nalong the forecast track. However, around 10 kt of easterly vertical\nwind shear may temper the rate of intensification during the next 24\nh or so. As the shear relaxes and Nolo continues to develop an inner\ncore, a faster rate of intensification is forecast while the cyclone\nmoves northward to north-northeastward during the next couple of\ndays. These conditions could support a period of rapid\nintensification, and Nolo is forecast to become a hurricane by\nThursday night and reach major hurricane strength on Saturday as it\npasses south of the Big Island. The latest NHC intensity forecast\nhovers near the upper end of the guidance envelope throughout the\nforecast period. A track closer to the Big Island could\nsubstantially increase the threat of damaging winds, particularly\nover higher terrain, along exposed ridges, and in areas downwind of\nthe ridges. \n \nKey Messages:\n \n1. Tropical Storm Nolo is expected to strengthen into a hurricane by \nThursday night as it moves northward to north-northeastward, \npotentially making its closest approach to the Big Island of Hawaii \nas a major hurricane on Saturday. A Hurricane Watch remains in \neffect for the Big Island, and residents there should follow advice \ngiven by local officials, including evacuating if told to do so.\n\n2. The time to prepare for significant heavy rain and flooding \nimpacts on the Big Island is now, as heavy rain becomes more likely \nby Thursday and Friday. Periods of heavy rain are likely to continue \nacross the Big Island and Maui through the weekend. \nLife-threatening, catastrophic flooding and mudslides are possible, \nespecially in areas of steep terrain across the Big Island and Maui. \nAcross the remainder of Hawaii, lesser rainfall totals are expected, \nwith isolated flooding possible.\n\n3. Large and damaging waves are possible along portions of the\nBig Island's coastline into the weekend.\n\n4. Interests elsewhere in Hawaii should closely monitor the latest\nforecast updates and ensure that they have their preparedness plans\nin place.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  24/0900Z 14.9N 156.0W   45 KT  50 MPH\n 12H  24/1800Z 15.1N 156.0W   55 KT  65 MPH\n 24H  25/0600Z 15.8N 155.7W   65 KT  75 MPH\n 36H  25/1800Z 16.7N 155.4W   75 KT  85 MPH\n 48H  26/0600Z 17.3N 155.3W   85 KT 100 MPH\n 60H  26/1800Z 17.6N 155.8W   95 KT 110 MPH\n 72H  27/0600Z 17.6N 157.1W  105 KT 120 MPH\n 96H  28/0600Z 18.1N 160.8W  105 KT 120 MPH\n120H  29/0600Z 20.3N 163.7W   95 KT 110 MPH\n \n"}