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#801919 (Received by flhurricane at: 4:40 AM 09.Sep.2015) TCDAT2 TROPICAL DEPRESSION GRACE DISCUSSION NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072015 500 AM AST WED SEP 09 2015 Grace is only producing a couple of small patches of disorganized convection this morning. An ASCAT-B overpass from several hours ago showed that the circulation has become elongated from east to west, and is less defined than it was yesterday. The scatterometer data also showed that the maximum winds are around 25 kt, and NOAA buoy 41041 has observed similar winds. Based on these data, the initial wind speed is lowered to 25 kt, which is also close to the latest satellite intensity estimates. The depression continues to battle west-southwesterly shear of about 20 kt and a fairly stable air mass. These conditions are expected to become even more hostile, which should cause the cyclone to degenerate to a remnant low or become a trough within the next day or two before it reaches the Lesser Antilles. This scenario is supported by nearly all of the models. The center of Grace appears to be located a little to the south of the previous track, and the initial motion estimate is due westward, or 270 degrees, at 15 kt. Grace, or its remnant, is expected to continue moving westward at about the same speed until it dissipates in a few days or less. The new NHC track forecast is a little south of the previous one, based mainly on the more southward initial position, and lies near the middle of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 09/0900Z 14.3N 47.2W 25 KT 30 MPH 12H 09/1800Z 14.5N 49.7W 25 KT 30 MPH 24H 10/0600Z 14.9N 53.2W 25 KT 30 MPH 36H 10/1800Z 15.4N 56.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 11/0600Z 15.9N 60.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 12/0600Z...DISSIPATED $$ Forecaster Cangialosi |