{"id": "1209216781533708290", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-11T03:00:00Z", "msg": "722\nWTPA44 PHFO 110234\nTCDCP4\n \nPost-Tropical Cyclone Lowell Discussion Number  60\nNWS Central Pacific Hurricane Center Honolulu HI   EP122026\nIssued by NWS National Hurricane Center Miami FL\n500 PM HST Thu Sep 10 2026\n \nIt has now been roughly 24 hours since Lowell produced more than \njust patches of deep convection on its northeast side. This activity \nhas lacked much organization over this time span, with continued \nwesterly vertical wind shear keeping the low-level circulation \nexposed. Given that Lowell has lacked organized convection near its \ncenter for about a day, and with most of the global and \nhurricane-regional model guidance not showing a return of deep \nconvection for at least another 24 h, Lowell is being declared a \npost-tropical cyclone this advisory. The maximum sustained winds \nremain 45 kt, however, based on scatterometer data received after \nthe prior advisory. \n\nThe post-tropical low is still moving westward at 270/12 kt. Much of \nthe forecast reasoning has not changed despite the cyclone's status \nchange, with a deep-layer cutoff low expected to pick up the \npost-tropical low, pinwheeling it around to the northwest, west, \nthen southward in the 24-72 h period. There continue to be \ndifferences in the model guidance on how sharp of a cyclonic turn \naround the upper-level low there will be, but ultimately the \nguidance shows the post-tropical low being deposited back south \nafter the upper-level feature bypasses it to the east in 72-96 h.  \n \nAs mentioned above, most of the model guidance does not show deep \nconvection returning near the post-tropical cyclone for the next day \nor so. However, an upper-level cutoff low is still forecast to drop \nsouthward and induce some sheared convection this weekend. However, \ngiven the disorganized state of the post-tropical cyclone, this \nbrief period of favorable convective forcing does not appear to last \nlong enough for the system to redevelop into a tropical cyclone, \nespecially given that the GFS and ECMWF-based SHIPS guidance shows \nvertical wind shear remaining in the 30-40 kt range. After the \nupper-level cutoff passes it by to the east, the low is expected to \nslowly fill, with much of the model guidance showing the low opening \nup into a trough by 120 h, which is now reflected in the NHC \nforecast.\n\nThis is the final advisory on Lowell unless regeneration occurs. For \nadditional information on the post-tropical low please see High Seas \nForecasts issued by the National Weather Service, under AWIPS header \nNFDHSFEPI, WMO header FZPN01 KWBC, and on the web at \nocean.weather.gov/shtml/NFDHSFEPI.php\n\n \nKEY MESSAGES:\n \n1. Post-storm safety: Follow advice of local officials and avoid\nareas of downed power lines and flooding. Ensure generators are\nproperly ventilated and placed outside at least 20 feet away from\ndwellings and garages to avoid carbon monoxide poisoning. During\nclean up, be careful when using chainsaws and power tools. Drink\nplenty of water to avoid heat exhaustion.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  11/0300Z 29.0N 169.9W   45 KT  50 MPH...POST-TROPICAL\n 12H  11/1200Z 29.2N 171.3W   40 KT  45 MPH...POST-TROPICAL\n 24H  12/0000Z 30.6N 172.0W   40 KT  45 MPH...POST-TROPICAL\n 36H  12/1200Z 32.7N 172.8W   45 KT  50 MPH...POST-TROPICAL\n 48H  13/0000Z 34.0N 175.0W   40 KT  45 MPH...POST-TROPICAL\n 60H  13/1200Z 33.6N 176.7W   35 KT  40 MPH...POST-TROPICAL\n 72H  14/0000Z 32.9N 177.0W   30 KT  35 MPH...POST-TROP/REMNT LOW\n 96H  15/0000Z 31.5N 176.6W   25 KT  30 MPH...POST-TROP/REMNT LOW\n120H  16/0000Z...DISSIPATED\n \n"}