000 WTPZ44 KNHC 080838 TCDEP4 Tropical Storm Sandra Discussion Number 4 NWS National Hurricane Center Miami FL EP192021 100 AM PST Mon Nov 08 2021 Sandra's convective pattern is characteristic of a sheared tropical cyclone, with the bulk of the convection now displaced into the northeastern quadrant of the cyclone owing to southwesterly vertical wind shear of around 20 kt. A 0257Z ASCAT-A pass revealed a tight, well-defined low-level circulation center, but with peak surface winds of only 28 kt in the northeastern quadrant. However, the intensity is being maintained at 35 kt since deep convection with cloud tops to -80C has re-developed in the vicinity of those ASCAT winds, possibly resulting in a local enhancement in those wind speeds. Conventional satellite fixes and the aforementioned ASCAT wind data indicate that Sandra's forward speed has slowed considerably, and the initial motion estimate is now 285/06 kt. The cyclone is forecast to remain along the southern periphery of a deep-layer subtropical ridge for the next few days, resulting in a slow west-northwestward motion today, followed by a westward turn on Tuesday with that motion continuing into Wednesday. The new NHC forecast track is a little to the left or south of the previous advisory track, and lies down the middle of the NHC guidance envelope, which a tad south of the consensus models. Moderate to strong southwesterly wind shear is expected to continue affecting Sandra for the next few days, while mid-level moisture and sea-surface temperatures gradually decrease. The combination of these unfavorable environmental conditions are expected to result in a gradual weakening of the cyclone, with Sandra now forecast to become a tropical depression later today and degenerate into a remnant low pressure system by late Tuesday. The new official intensity forecast is essentially the same as the previous advisory, and closely follows a blend of HCCA and IVCN intensity consensus models and the GFS and ECMWF global models. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 14.1N 116.3W 35 KT 40 MPH 12H 08/1800Z 14.5N 117.5W 30 KT 35 MPH 24H 09/0600Z 14.9N 119.1W 30 KT 35 MPH 36H 09/1800Z 14.8N 121.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 10/0600Z 14.6N 123.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 10/1800Z...DISSIPATED $$ Forecaster Stewart