{"id": "1213325694875598855", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-25T15:00:00Z", "msg": "141\nWTPA42 PHFO 251453\nTCDCP2\n \nHurricane Nolo Discussion Number  20\nNWS Central Pacific Hurricane Center Honolulu HI   EP152026\nIssued by NWS National Hurricane Center Miami FL\n500 AM HST Fri Sep 25 2026\n\nNolo continues on a gradual strengthening trend this morning.  On \nthe last pass through the hurricane, Air Force Hurricane Hunters \nreported that the pressure had dropped to about 980 mb, and  \nsatellite imagery shows deepening convection in the ragged eyewall. \nOn this basis, the initial intensity is set to 75 kt, which is also \nat the top end of the various satellite estimates.\n\nThe hurricane is moving north-northeastward at 4 kt, as it is being \nsteered by a deep-layer trough located west of the Hawaiian Islands. \nThis trough should begin to move away from Nolo on Saturday, \ncausing the hurricane to drift westward while it is located south of \nHawaii.  A westward motion with increasing forward speed is then \nexpected by early Sunday due to a ridge re-building.  Model \nguidance has, unfortunately, not been very consistent on exactly \nwhen this westward turn occurs, as there has been a shift to the \nnorth on this cycle.  This new forecast is moved in that direction \nthrough the weekend, though still a fair distance south of Hawaii.  \nAt long range, Nolo should again encounter the aforementioned \nupper-level trough, now re-invigorated, which should cause a \nnorth-northwestward turn early next week.  No significant changes \nwere made to the long-range NHC forecast. \n\nNolo should further intensify today, though rapid intensification is \nnot expected due to its large radius-of-maximum wind, moderate \nshear and some dry mid-level air in the northern semicircle.  The \nshear is forecast to weaken in about 36 hours, which should allow \nthe hurricane to significantly intensify.  Additionally, Nolo could \nbe moving over a patch of high ocean heat content, and model \nguidance is in better agreement on this system becoming rather \nstrong by early next week.  The new forecast is similar to the \nprevious one but raised just a bit through day 3 to come into \nbetter agreement with the typically skillful HCCA model. Weakening \nis expected by days 4 and 5 due to forecast strong southwesterly \nshear east of the trough.\n \n \nKey Messages:\n \n1. Nolo is expected to remain south of the Big Island of Hawaii \nthrough Saturday before turning westward and moving away from the \nisland. Tropical storm conditions are expected to begin on the Big \nIsland tonight with hurricane conditions possible on Saturday, \nparticularly in areas of steep terrain. Residents should follow \nadvice given by local officials, including evacuating if told to do \nso.\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. Periods of heavy rain are \nexpected 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  25/1500Z 16.0N 155.5W   75 KT  85 MPH\n 12H  26/0000Z 16.7N 155.3W   90 KT 105 MPH\n 24H  26/1200Z 17.1N 155.5W   95 KT 110 MPH\n 36H  27/0000Z 17.1N 156.3W  100 KT 115 MPH\n 48H  27/1200Z 16.9N 157.8W  110 KT 125 MPH\n 60H  28/0000Z 16.9N 159.8W  120 KT 140 MPH\n 72H  28/1200Z 17.4N 161.6W  120 KT 140 MPH\n 96H  29/1200Z 20.2N 164.3W  100 KT 115 MPH\n120H  30/1200Z 22.7N 164.8W   70 KT  80 MPH\n \n"}