000 WTNT42 KNHC 290853 TCDAT2 TROPICAL STORM BONNIE DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL022016 500 AM EDT SUN MAY 29 2016 Shortly after Bonnie reached its peak intensity of 40 kt, water vapor imagery and satellite-derived winds indicate that a surge of 40-60 kt upper-level winds passed over the center of the cyclone, which stripped away all of the associated deep convection. In addition, an intrusion of dry air has inhibited the redevelopment of significant deep convection near the center. Based on the erosion of the convective pattern, the intensity has been lowered to 35 kt for this advisory. Radar and satellite imagery suggest that Bonnie is now moving due north or 360/07 kt. Bonnie has become a more shallow tropical cyclone due to the loss of all deep convection, and the system is expected to be steered generally northward around the western periphery of a low-level ridge for the next 24 hours or so. This should bring the center of Bonnie near or just inland of the South Carolina coast this afternoon or tonight. After that, Bonnie is expected to move slowly northeastward around the northern side of the Bermuda-Azores High and emerge out over the Atlantic by 36 to 48 hours, and continue moving northeastward or east-northeastward through the remainder of the forecast period. The NHC track forecast is similar to the previous advisory track, and closely follows a blend of the GFS and ECMWF model tracks. Continued strong southerly vertical wind shear, along with dry air in the mid- and upper-levels and proximity to land, should prevent any significant restrengthening from occurring. However, there could be intermittent bursts of convection near the center of Bonnie, keeping the cyclone as a tropical storm until landfall occurs later today. By 48 hours and beyond, environmental conditions worsen, and Bonnie is expected to degenerate into a remnant low pressure system by 72 hours, if not sooner. The primary impact from Bonnie will be locally heavy rainfall, which is already occurring over much of South Carolina, eastern Georgia, and portions of southeastern North Carolina. These rains will gradually spread northeastward along the mid-Atlantic region over the next couple of days. FORECAST POSITIONS AND MAX WINDS INIT 29/0900Z 32.1N 79.4W 35 KT 40 MPH 12H 29/1800Z 32.6N 79.6W 35 KT 40 MPH 24H 30/0600Z 33.3N 79.6W 35 KT 40 MPH...INLAND 36H 30/1800Z 33.5N 78.9W 30 KT 35 MPH...OVER WATER 48H 31/0600Z 33.9N 78.0W 30 KT 35 MPH 72H 01/0600Z 34.5N 76.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 02/0600Z 35.2N 75.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 03/0600Z 35.8N 74.4W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart