{"id": "1208933329035231234", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-10T03:00:00Z", "msg": "139\nWTPA44 PHFO 100232\nTCDCP4\n \nTropical Storm Lowell Discussion Number  56\nNWS Central Pacific Hurricane Center Honolulu HI   EP122026\nIssued by NWS National Hurricane Center Miami FL\n500 PM HST Wed Sep 09 2026\n\nLowell's convective structure on satellite imagery is not very \nimpressive, consisting of a well-defined low-level swirl with some \ncolder cloud tops attempting to form on the northeast side of the \ncirculation. The storm is clearly being negatively impacted by \nmoderate westerly shear importing nearby dry air and marginally warm \nsea-surface temperatures. Scatterometer data received after the \nprior advisory indicated a robust surface wind field remains, with \npeak wind-retrievals in the 45 to 50 kt range. However, subjective \nand objective satellite estimates continue to decrease, and assuming \nthe low-level circulation continues to spin down without much deep \nconvection, the initial intensity is set to 45 kt for this advisory.\n\nThe tropical cyclone has turned westward, with the estimated motion \nnow 280 degrees at 12 kt. Lowell is now being steered primarily by a \nlow- to mid-level ridge located north of the tropical storm, and \nthis should maintain a general westward motion over the next 24-36 \nh. After that time, a mid- to upper-level trough located northwest \nof Lowell is anticipated to cutoff and interact with the cyclone, \nwith the track guidance coming into better agreement that this will \nlead to a sharp turn to the northwest or north in 60-72 h. By the \nend of the forecast period, the upper-level cutoff low moves east \nof Lowell, leaving behind a shallow low-level circulation sandwiched \nbetween two low-level ridges. The track guidance responds to this \nchange by indicating a slow southward drift as the cyclone becomes a \nremnant low. The NHC track forecast is very similar to the prior one \nfor the first 2-3 days, but shows a sharper turn southward \nby the end of the forecast. This track is closest to the Google \nDeepMind (GDMI) and HFIP Corrected Consensus Approach (HCCA) aids.  \n\nModerate westerly vertical wind shear, abundant dry air, and only \nmarginally warm sea-surface temperatures are likely to lead to \nfurther weakening over the next 36 h. In fact, Lowell could struggle \nto produce enough convection to be considered a tropical cyclone \nduring this period. Nonetheless, the aforementioned trough \ninteraction in the 2-3 day time frame will likely reinvigorate some \nconvection on the storm's down-shear side via baroclinic processes, \nwhich could help intensify Lowell's wind field. Most of the \nintensity guidance shows at least some intensification during this \nperiod of interaction, and the NHC intensity forecast was adjusted \nsomewhat to reflect this solution, though it remains below the \nHAFS-A/B hurricane models. After 72 h, the upper-level low \ninteracting with Lowell will pass it to the east, leaving the storm \nin an area of enhanced subsidence that will likely diminish the \nremaining convection when the storm will be over sub-26 C SSTs. \nThus, the latest NHC forecast still shows Lowell becoming a \npost-tropical low in 96 h. There is still a healthy amount of track \nuncertainty towards the end of the forecast, though the guidance is \ncoming into better agreement on Lowell losing its tropical \ncharacteristics by this time.\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  10/0300Z 29.2N 165.1W   45 KT  50 MPH\n 12H  10/1200Z 29.3N 167.1W   40 KT  45 MPH\n 24H  11/0000Z 29.2N 169.5W   35 KT  40 MPH\n 36H  11/1200Z 29.4N 171.2W   35 KT  40 MPH\n 48H  12/0000Z 30.6N 172.0W   40 KT  45 MPH\n 60H  12/1200Z 32.2N 172.4W   45 KT  50 MPH\n 72H  13/0000Z 33.3N 173.4W   40 KT  45 MPH\n 96H  14/0000Z 32.8N 175.1W   30 KT  35 MPH...POST-TROP/REMNT LOW\n120H  15/0000Z 31.6N 175.4W   25 KT  30 MPH...POST-TROP/REMNT LOW\n \n"}