{"id": "1203626726452690946", "title": "Tropical Cyclone Discussion", "adv_date": "2026-08-22T09:00:00Z", "msg": "634\nWTPA42 PHFO 220842\nTCDCP2\n \nHurricane Lala Discussion Number  40\nNWS Central Pacific Hurricane Center Honolulu HI   CP012026\nIssued by NWS National Hurricane Center Miami FL\n1100 PM HST Fri Aug 21 2026\n \nLala's structure has evolved over the past 6-12 hours due to\ninteraction with an upper-level trough to its west and southwest.\nDeep convection has been sheared away from the center due to nearly\n30 kt of south-southwesterly shear, and moderate convection now\nwraps around the northern and western side of the circulation,\nvery similar to the structure of an occluded extratropical low.\nDvorak Current Intensity numbers from HFO and JTWC are still 4.5/77\nkt, and given that winds can be slow to decrease when a tropical\ncyclone positively interacts with an upper-level trough, the\ncurrent intensity estimate remains 75 kt. It is estimated that\nLala's wind field has also expanded as a result of the trough\ninteraction. A pair of ASCAT passes should hit the cyclone soon to\ngive us a better estimate of Lala's intensity and size.\n \nThe interaction with the trough has also caused Lala to turn and\ntemporarily accelerate toward the northwest (325/12 kt). A mid-level\nridge to the northeast should force the cyclone on a northwestward\ntrajectory for the next 3 days, but the steering is so weak that\nLala is likely to slow down considerably, only moving at 4-5 kt on\nSunday and Monday. A motion toward the north-northwest could occur\nby Tuesday and Wednesday as the ridge shifts east of Lala, but\nthere is model spread regarding the degree and speed of that turn.\nThe NHC track forecast lies just left of the center of the guidance\nenvelope, leaning toward the HCCA and GDMI guidance, and is also not\nvery different from the previous forecast.\n \nDeep-layer shear is forecast to fall to 10 kt or less in about 12\nhours once Lala becomes embedded within the larger-scale longwave\ntrough. Since the hurricane is expected to slow down, water\ntemperatures and atmospheric instability are only expected to\ngradually decrease during the next few days, which should allow for\nat least moderate convection to continue. The NHC intensity\nforecast continues to show gradual weakening, generally close to\nthe IVCN intensity consensus, and Lala could still be a tropical\ncyclone at the end of the 5-day forecast period.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  22/0900Z 30.3N 172.0W   75 KT  85 MPH\n 12H  22/1800Z 31.3N 172.7W   70 KT  80 MPH\n 24H  23/0600Z 32.2N 173.6W   65 KT  75 MPH\n 36H  23/1800Z 33.0N 174.4W   60 KT  70 MPH\n 48H  24/0600Z 33.6N 175.0W   55 KT  65 MPH\n 60H  24/1800Z 34.3N 175.6W   50 KT  60 MPH\n 72H  25/0600Z 35.1N 176.4W   45 KT  50 MPH\n 96H  26/0600Z 36.8N 178.1W   45 KT  50 MPH\n120H  27/0600Z 38.9N 179.4W   40 KT  45 MPH\n \n"}