{"id": "1205324444686385154", "title": "Tropical Cyclone Discussion", "adv_date": "2026-08-28T09:00:00Z", "msg": "821\nWTPZ41 KNHC 280837\nTCDEP1\n \nTropical Storm Karina Discussion Number   3\nNWS National Hurricane Center Miami FL       EP112026\n200 AM MST Fri Aug 28 2026\n \nKarina's structure on satellite imagery tonight is slowly evolving,\nwith a concentrated burst of deep convection with cloud top\ntemperatures below -80 C occurring near and to the east of the\ncenter. However, scatterometer wind data around 05 UTC indicated\nthat the center was still on the edge of this convective burst, and\nremains a bit elongated on its southwest end, where the cyclone is\ninteracting with the larger monsoon trough. The peak wind retrieval\nwas 41 kt, and that combined with little change in the subjective\nor objective intensity estimates supports maintaining 45 kt for this\nadvisory.\n \nThe tropical storm is moving on a general northwest heading at \n310/11 kt. An established mid-level ridge over the southwestern U.S. \nshould maintain this general motion over the next couple of days. \nThereafter, this ridging begins to extend more zonally to the north \nof Karina, allowing the track of the cyclone to turn more westward \nin the 48-72 h time frame. Towards the end of the forecast period, \nguidance suggests this ridge will become eroded by a mid- to \nupper-level trough, which could result in Karina making a turn back \nto the northwest. The track guidance this morning has shifted a \nlittle south and west compared to the previous cycle, and the NHC \nforecast track has also been shifted in this direction, blending the \nlatest HFIP Corrected Consensus Approach (HCCA) and Google DeepMind \n(GDMI) aids.\n\nKarina's wind field diagnosed by scatterometer earlier is still \nfairly broad, and it will likely take a bit more time for the \ncyclone to develop an inner core. However, environmental conditions \nbeyond the next 24 h remain quite favorable for intensification, \nwith low shear, warm waters, and a sufficiently moist deep-layer \ntroposphere. SHIPS-RII guidance also continues to indicate elevated \nprobabilities of rapid intensification that are 4-5 times the \nclimatological mean. Thus, significant intensification is forecasted \nover the next 2-3 days, and the latest NHC intensity forecast is \nhigher than the previous one, showing a 110 kt peak in about 72 h, \nthough this forecast is still under some of the more aggressive \nguidance (HCCA, GDMI) but above some of the hurricane-regional model \nguidance this cycle (HAFS-A/B). In days 4-5 Karina should encounter \na more stable environment as it approaches the northern edge of the \n26 C isotherm, and weakening is shown to begin by the end of the \nforecast period.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  28/0900Z 12.7N 114.3W   45 KT  50 MPH\n 12H  28/1800Z 13.6N 115.5W   55 KT  65 MPH\n 24H  29/0600Z 15.1N 116.9W   65 KT  75 MPH\n 36H  29/1800Z 16.5N 118.9W   80 KT  90 MPH\n 48H  30/0600Z 17.5N 120.7W   90 KT 105 MPH\n 60H  30/1800Z 18.2N 122.5W  100 KT 115 MPH\n 72H  31/0600Z 18.4N 124.2W  110 KT 125 MPH\n 96H  01/0600Z 19.3N 127.3W  100 KT 115 MPH\n120H  02/0600Z 20.5N 129.5W   80 KT  90 MPH\n \n"}