{"id": "1213183909705515015", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-25T03:00:00Z", "msg": "213\nWTPA42 PHFO 250252\nTCDCP2\n \nHurricane Nolo Discussion Number  18\nNWS Central Pacific Hurricane Center Honolulu HI   EP152026\nIssued by NWS National Hurricane Center Miami FL\n500 PM HST Thu Sep 24 2026\n \nNolo's structure on satellite imagery continues to gradually \nimprove with a banding-type eye trying to develop on visible \nsatellite imagery. The Air Force Reserve Hurricane Hunters have been \nflying through Nolo this afternoon, and found a peak flight-level \nwind of 71 kt and a minimum central pressure down to 984 mb in their \nmost recent fix. These values are enough to upgrade Nolo to a \nhurricane this advisory, with an initial intensity of 65 kt. \n \nThe storm is finally moving more consistently to the north-northeast \nwith an estimated motion at 020 degrees at 4 kt. There is little \nchange to the track reasoning this cycle, with a deep-layer trough \nlocated to the northwest of Nolo helping to steer it slowly to the \nnorth-northeast over the next 24-36 h. Thereafter, this trough cuts \noff to the west of the Hawaiian islands and moves westward out of \nthe way, allowing mid-level ridging to build back in north of Nolo. \nThe net result of this synoptic change is that Nolo is expected to \nmake a sharp turn to the west, or even west-southwest in the 48-72 h \ntime frame. However, the aforementioned cutoff low still limits how \nfar west this mid-level ridging is able to extend, and Nolo will \nlikely begin to gain latitude in the day 4-5 day time frame. The \ntrack guidance has made a rather substantial southward shift \ncompared to the previous cycle, and the NHC track forecast has been \nshifted southward, though it remains on the northern side of the \nguidance envelope. This track forecast lies closest to the Google \nDeepMind ensemble mean (GDMI) which is actually a northern outlier \nthis cycle, so it's possible future southward adjustments may be \nnecessary.\n\nEven though Nolo is now a hurricane, the Air Force Reconnaissance \naircraft has yet to report a closed eyewall in either of its fixes \nthrough the hurricane, and the wind field is a little bit on the \nbroader side. However, environmental conditions appear quite \nfavorable with low shear, sufficently warm sea-surface temperatures \nand enough deep-layer moisture to support robust intensification. \nThe NHC intensity forecast continues to forecast significant \nintensification, and now shows a peak intensity of 115 kt as Nolo \nturns westward in the 48-72 h time frame. This intensity forecast \nis a blend of the latest HFIP Corrected Consensus Approach (HCCA) \nand HAFS-A/B runs, even though the HCCA remains the highest outlier \nin the intensity guidance this cycle. At long range, vertical wind \nshear is expected to increase, and the NHC intensity shows \nweakening beginning by day 5. \n \nKey Messages:\n \n1. Nolo is expected to pass near or just south of the Big Island of \nHawaii on Saturday as a major hurricane.  Tropical storm conditions \nare expected to begin on the Big Island Friday night with hurricane \nconditions possible on Saturday, particularly in areas of steep \nterrain.  Residents should follow advice given by local officials, \nincluding evacuating if told to do so.\n \n2. The time to finish preparations for significant heavy rain and \nflooding impacts on the Big Island is now as heavy rain increases in \nboth coverage and intensity today and Friday. Periods of heavy rain \nare expected to continue across the Big Island and Maui through the \nweekend. Life-threatening, catastrophic flooding and mudslides are \npossible, especially in areas of steep terrain across the eastern \nand southern portions of the Big Island and Maui. Across the \nremainder of Hawaii, lesser rainfall totals are expected, with \nisolated flooding possible. \n \n3. Large and damaging waves are likely along portions of the\nBig Island's coastline into the weekend.\n \n4. A Tropical Storm Watch is in effect for Maui County where\ntropical storm conditions are possible beginning on Saturday.\nInterests 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  25/0300Z 15.1N 155.9W   65 KT  75 MPH\n 12H  25/1200Z 15.7N 155.6W   75 KT  85 MPH\n 24H  26/0000Z 16.6N 155.3W   85 KT 100 MPH\n 36H  26/1200Z 17.1N 155.4W   95 KT 110 MPH\n 48H  27/0000Z 17.0N 156.1W  100 KT 115 MPH\n 60H  27/1200Z 16.9N 157.7W  110 KT 125 MPH\n 72H  28/0000Z 16.9N 159.7W  115 KT 130 MPH\n 96H  29/0000Z 18.6N 163.0W  115 KT 130 MPH\n120H  30/0000Z 21.7N 164.8W   90 KT 105 MPH\n \n"}