{"id": "1212830846260314119", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-23T21:00:00Z", "msg": "099\nWTPA42 PHFO 232056\nTCDCP2\n \nTropical Storm Nolo Discussion Number  13\nNWS Central Pacific Hurricane Center Honolulu HI   EP152026\nIssued by NWS National Hurricane Center Miami FL\n1100 AM HST Wed Sep 23 2026\n \nThe system has continued to become better organized this morning, \nwith tighter curved banding features noted on satellite imagery.  \nThe low-level circulation remains on the southeastern side of most \nof the deep convection.  Satellite estimates are rising, and the \nbulk of the values now show this at or above 35 kt.  The initial \nintensity is set to 35 kt, marking the formation of a tropical \nstorm. \n\nNolo is moving west-northwestward at about 5 kt.  There is no \nchange to the synoptic reasoning with a ridge located to the \nnortheast of Hawaii forecast to weaken and push eastward as a mid-\nlatitude trough deepens over the northwestern Hawaiian islands.\nThis pattern is likely to the cause Nolo to slow down tonight and \nthen turn north-northeastward by tomorrow with some increase in \nforward speed.  The trough is forecast to move westward this weekend \nas the ridge rebuilds north of Hawaii, which should force a sharp \nleftward turn while the cyclone is close to the Big Island.  It \nreally depends on how far northeast Nolo gets before the ridge \nrebuilds, with the solutions that gain the most latitude in the \nnext few days generally getting closest to Hawaii.  Although there \nhas been a small southward shift in the overall guidance on this \ncycle, there is still a large spread approaching 250 n mi from \nnorth-to-south by the weekend.  The new forecast is nudged south on \nthis advisory, but it should be considered low confidence.\n\nThe current disorganized structure would seem to promote only slow \nstrengthening during the next day or so under otherwise favorable \nenvironmental conditions.  However, the system is likely to \ndevelop an inner core on Thursday, which could support rapid \nintensification given very warm waters, low shear and high \nmid-level moisture values.  Intensity guidance is a little higher \nthan the last cycle, and the NHC forecast is raised slightly from \nday 3 and beyond, showing a major hurricane near and west of Hawaii.\n \nKey Messages:\n \n1. Tropical Storm Nolo is expected to strengthen into a hurricane \non Thursday as it moves northward, potentially making its closest \napproach to the Big Island of Hawaii on Saturday. A Hurricane Watch \nis now in effect for the Big Island, and residents there should \nfollow advice given by local officials, including evacuating if told \nto 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 \ncontinue across 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 the coast of the Big \nIsland into the weekend.\n\n4. Interests elsewhere in Hawaii should closely monitor the latest \nforecast updates and ensure that they have their preparedness plan \nin place. \n \n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  23/2100Z 14.5N 155.3W   35 KT  40 MPH\n 12H  24/0600Z 14.7N 155.6W   40 KT  45 MPH\n 24H  24/1800Z 15.1N 155.6W   50 KT  60 MPH\n 36H  25/0600Z 15.8N 155.2W   65 KT  75 MPH\n 48H  25/1800Z 16.7N 154.8W   80 KT  90 MPH\n 60H  26/0600Z 17.5N 154.8W   90 KT 105 MPH\n 72H  26/1800Z 17.8N 155.6W  100 KT 115 MPH\n 96H  27/1800Z 17.6N 158.5W  105 KT 120 MPH\n120H  28/1800Z 18.8N 161.8W  100 KT 115 MPH\n \n"}