{"id": "1206528491990548483", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-01T15:00:00Z", "msg": "659\nWTPZ43 KNHC 011441\nTCDEP3\n \nTropical Storm Marie Discussion Number   2\nNWS National Hurricane Center Miami FL       EP132026\n800 AM MST Tue Sep 01 2026\n \nThis morning's GOES-18 Proxy-VIS satellite imagery indicates that\nMarie is gradually becoming better organized.  Deep convection with \ncold cloud tops of -81C is developing over the surface circulation \ncenter, and a spiral band is wrapping around the center from the \nsouthwest part of the cyclone.  No changes yet in both the \nsubjective and objective satellite intensity guidance, however, so \nthe initial intensity is held at 40 kt for this advisory.\n \nThe ocean is warm, the low- to mid-levels of the atmosphere are\nmoist, and the deep-layer shear is low.  Subsequently, strengthening\nis expected, and Marie should become a hurricane by Wednesday \nnight.  By the weekend, the GFS/ECMWF SHIPS statistical intensity \nguidance and the physics-based deterministic models indicate that \nMarie will encounter a drier, stable marine layer air mass while \ntraversing progressively cooler oceanic temperatures.  Accordingly, \nthe NHC intensity forecast follows suit and shows Marie slowly \nweakening beyond day 4.\n \nAn earlier 0707 UTC OSCAT-3 scatterometer overpass and a\nfortuitous 1247 UTC GPM/GMI image indicated that the surface center \nwas a bit farther northeast than previously noted, and near \nthe northwestern edge of the deep convective canopy.  Marie's \ninitial motion is estimated to be northwestward, or 315/8 kt.  A \nmid-tropospheric subtropical ridge stretching from northern\nMexico westward over the extreme eastern Pacific should steer\nthe cyclone generally northwestward through Thursday.  \nAfterward, the subtropical high should weaken in response to an \namplifying mid- to upper-level trough approaching the west coast of \nthe U.S. This change in the large-scale synoptic pattern is \nexpected to slow Marie's forward speed.  For the remainder of the \nforecast, the aforementioned mid- to upper-level trough should fill \nand lift northeastward, allowing the ridge to build and reestablish \nnorth of Marie and steer the system back toward the west-northwest \nthrough the weekend.  There's still quite a bit of cross-track \nspread in the model suite beyond day 3, with one cluster indicating \na north-northwestward motion while another model cluster shows a \nmore west-northwestward trajectory.  The official forecast reflects \nslight adjustments to the left of the previous forecast and favors \na blend of the skilled NOAA HCCA consensus aid and the Google \nDeepMind FNv3 ensemble mean forecast.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  01/1500Z 15.0N 108.7W   40 KT  45 MPH\n 12H  02/0000Z 16.0N 109.8W   50 KT  60 MPH\n 24H  02/1200Z 17.1N 111.2W   60 KT  70 MPH\n 36H  03/0000Z 18.0N 112.4W   70 KT  80 MPH\n 48H  03/1200Z 19.0N 113.9W   80 KT  90 MPH\n 60H  04/0000Z 19.7N 115.6W   85 KT 100 MPH\n 72H  04/1200Z 20.3N 117.0W   85 KT 100 MPH\n 96H  05/1200Z 21.4N 119.8W   80 KT  90 MPH\n120H  06/1200Z 22.3N 122.0W   75 KT  85 MPH\n \n"}