ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM Tropical Storm Marie Discussion Number 29 NWS National Hurricane Center Miami FL EP182020 1100 PM HST Mon Oct 05 2020 A 6/0630Z ASCAT-B scatterometer overpass indicated that Marie has refused to weaken despite the deep convection being severely sheared to the northeast of the low-level center. A solid area of 40-kt was present northwest through northeast of the center, with a couple of 45-kt vectors present. However, the 45-kt vectors look like they could have been rain enhanced, so the initial intensity remains at 40 kt for this advisory. The initial motion estimate is 300/08 kt. There are no significant changes to the previous forecast track or reasoning. Marie is expected to move slowly west-northwestward along the southern periphery of a deep-layer ridge for the next 24 hours or so, during which time the cyclone will gradually spin down and become more vertically shallow. Thereafter, and continuing until dissipation occurs, a more westward motion is anticipated when the shallow system will be steered by the low-level easterly tradewind flow. The new NHC forecast track is similar to but a tad north of the previous advisory track, and lies near the middle of the tightly packed consensus aids. Although Marie has managed to survive some horrendous southwesterly vertical wind of at least 30 kt, the cyclone is not long for this world due to the shear increasing further while the cyclone moves over sub-25 deg C sea-surface temperatures for the next few days. These very unfavorable environmental conditions should result in all convection being stripped away by late Tuesday morning, causing Marie to degenerate into a 35-kt post-tropical cyclone. Further weakening is anticipated, with Marie becoming a remnant low by Tuesday night and dissipating by late Friday or Saturday over the far western portion of the eastern Pacific basin. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 21.7N 134.3W 40 KT 45 MPH 12H 06/1800Z 22.2N 135.5W 35 KT 40 MPH...POST-TROPICAL 24H 07/0600Z 22.7N 136.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 07/1800Z 23.0N 137.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 08/0600Z 23.2N 138.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 60H 08/1800Z 23.1N 139.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 09/0600Z 23.2N 140.8W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 10/0600Z...DISSIPATED $$ Forecaster Stewart NNNN