{"id": "1204476315538030595", "title": "Tropical Cyclone Discussion", "adv_date": "2026-08-25T09:00:00Z", "msg": "214\nWTPZ44 KNHC 250843\nTCDEP4\n \nTropical Storm Iselle Discussion Number   8\nNWS National Hurricane Center Miami FL       EP092026\n200 AM PDT Tue Aug 25 2026\n \nThe infrared satellite presentation of Iselle remains steady early \nthis morning, featuring an established curved band with very cold \ncloud tops of -75C to -80C that wraps about halfway around the \nstorm. Moderate westerly wind shear continues to impact the system. \nEarlier microwave imagery showed an established core north and east \nof the center, although the western portion of the circulation was \nless defined. An ASCAT-B pass from earlier tonight indicated maximum \nwinds of 53-56 kt, along with slightly larger 34-kt wind radii in \nthe northeast, southeast and northwest quadrants. Recent objective \nand subjective Dvorak intensity estimates range from 51-63 kt. Given \nthe steady satellite presentation and ASCAT data, and after blending \nthe subjective and objective intensity estimates, the initial \nintensity is maintained at 60 kt for this advisory. The ASCAT data \nalso indicated that Iselle is located farther northwest and moving \nslightly faster than previously estimated.\n\nThe tropical storm is moving northwestward around 13 kt. A turn \ntoward the west-northwest, accompanied by a slight decrease in \nforward speed, is expected later today as mid-level ridging \ncurrently centered over the southern United States strengthens and \nexpands westward into the eastern Pacific. This general heading is \nexpected to continue over the next several days. The latest NHC \ntrack forecast has been shifted slightly to the left and is faster \nthan the previous advisory to account for the adjustment to the \ninitial position. The forecast remains near the middle of the track \nguidance envelope and is closest to the Google DeepMind Ensemble \nMean (GDMI).\n\nIselle is currently moving over warm waters near 28 C and remains \nwithin a relatively moist mid-level environment, and has likely \nreached its peak intensity. As the storm moves west-northwestward, \nprogressively cooler waters, increasing dry mid-level air, continued \nwesterly wind shear and increasingly unfavorable upper-level winds \nare expected to cause gradual weakening over the next several \ndays. The latest NHC intensity forecast calls for Iselle to weaken \nto a tropical depression by 60 h, and a post-tropical remnant low by \n72 h. However, the ECMWF and GFS simulated satellite imagery suggest \nthat Iselle could struggle to maintain organized deep convection \nbefore that time, raising the possibility that the cyclone could \nbecome post-tropical earlier than currently forecast. \n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  25/0900Z 20.7N 119.9W   60 KT  70 MPH\n 12H  25/1800Z 21.3N 121.4W   55 KT  65 MPH\n 24H  26/0600Z 21.9N 123.2W   50 KT  60 MPH\n 36H  26/1800Z 22.7N 124.9W   45 KT  50 MPH\n 48H  27/0600Z 23.4N 126.8W   35 KT  40 MPH\n 60H  27/1800Z 23.9N 128.8W   30 KT  35 MPH\n 72H  28/0600Z 24.3N 130.7W   25 KT  30 MPH...POST-TROP/REMNT LOW\n 96H  29/0600Z...DISSIPATED\n \n"}