{"id": "1221886465401782275", "title": "Tropical Cyclone Discussion", "adv_date": "2026-10-25T21:00:00Z", "msg": "655\nWTPA43 PHFO 252035\nTCDCP3\n \nTropical Storm Olana Discussion Number   2\nNWS Central Pacific Hurricane Center Honolulu HI   CP032026\nIssued by NWS National Hurricane Center Miami FL\n1100 AM HST Sun Oct 25 2026\n\nSince the prior advisory, convective activity has continued to \nexpand near and to the northeast of the estimated center of the \ntropical cyclone, with first light visible imagery indicating that \nthe center is likely embedded in this mass of deep convection. A \nhelpful WSF-M pass at 18 UTC also showed further organization, with \na curved band on its northwest flank, though some northeast tilt \nwith height is also noted between the 37 GHz and 89 GHz channels. \nThe latest subjective Dvorak intensity estimates were T1.5/25 kt \nfrom JTWC and T2.0/30 kt from HFO. However, the objective intensity \nestimates from UW-CIMSS range from 30-36 kt, and given the \nimprovement seen on satellite and microwave imagery since the prior \nadvisory, the initial intensity is set on the higher side of the \nintensity estimates at 35 kt, making the depression Tropical Storm \nOlana.\n \nOlana is estimated to be moving a bit faster to the east-northeast \nthis morning, or 075/7 kt. The track reasoning is the same as this \nmorning, with the combination of a low-level westerly wind burst to \nthe south and a mid-latitude trough to the northwest expected to \nmaintain the tropical storm on a general eastward track. The track \nguidance this cycle has shifted slower compared to the previous \nadvisory, as the circulation becomes more vertically shallow, and \nthe NHC track was also made slower than the previous forecast. The \nlatest track forecast is on the northern side of the guidance \nenvelope, favoring a blend of the faster HFIP Corrected Consensus \nApproach (HCCA) and slower ECMWF (EMXI) track guidance. Based on the \nlatest track forecast, no watches are required for Johnston Atoll at \nthis time, though interests there should continue to monitor the \nlatest forecast updates related to this system.\n \nThere remains a small window for Olana to intensify a bit more in \nthe short-term given its current structure, though the noted tilt \nwith height seen on the WSF-M microwave pass is likely a harbinger \nof stronger vertical wind shear that the tropical cyclone will soon \nbegin to experience. While both the GFS and EC-based SHIPS guidance \nare only forecasting 10-15 kt of deep-layer (200-850 mb) westerly \nshear over the next 12-36 h, the adjusted shear is much higher, \nsuggesting higher shear undercutting the outflow layer. Weakening is \nexpected to begin in 12-24 h, and this will likely be hastened when \nthe deep-layer shear increases above 30 kt in 48-60 h. Both the GFS \nand ECMWF simulated IR show the remaining convection being fully \nstripped away from Olana's circulation during this period. Thus, the \nNHC intensity forecast shows Olana becoming a remnant low by 60 h, \nwith the low opening up into a trough after 72 h, though the global \nmodels suggest the circulation could become too elongated to be \nconsidered well-defined earlier than shown here. \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  25/2100Z 14.8N 178.0W   35 KT  40 MPH\n 12H  26/0600Z 14.9N 177.2W   40 KT  45 MPH\n 24H  26/1800Z 14.4N 176.2W   35 KT  40 MPH\n 36H  27/0600Z 14.1N 175.3W   35 KT  40 MPH\n 48H  27/1800Z 14.3N 173.9W   30 KT  35 MPH\n 60H  28/0600Z 15.0N 172.8W   25 KT  30 MPH...POST-TROP/REMNT LOW\n 72H  28/1800Z 15.6N 172.0W   25 KT  30 MPH...POST-TROP/REMNT LOW\n 96H  29/1800Z...DISSIPATED\n \n"}