Show Selection: |
#797854 (Received by flhurricane at: 4:49 AM 24.Aug.2015) TCDAT4 TROPICAL STORM DANNY DISCUSSION NUMBER 24 NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015 500 AM AST MON AUG 24 2015 Reports from a NOAA Hurricane Hunter aircraft investigating Danny this morning indicate that Danny still has winds that support keeping the cyclone as a tropical storm. However, due to a strong burst of deep convection containing tops of -80 deg C and intense lightning activity that has developed near the alleged center, the aircraft has been unable to provide an exact center fix. This avoidance is for aircrew and aircraft safety reasons. However, satellite intensity estimates of T2.5/35 kt from TAFB and SAB also support keeping Danny as a tropical storm. The initial motion estimate is a slower 275/08 kt. UW-CIMSS shear analyses indicate that Danny is now encountering west-northwesterly mid-level shear of around 5 kt, which could explain the slow down in forward speed since the previous advisory. That being said, there is no significant change to the previous track forecast or reasoning. The subtropical ridge to the north of the cyclone is expected to remain strong for the next few days, which should force Danny on a westward to west-northwestward track until the system dissipates in about 72 hours. The official track forecast is basically just an update and extension of the previous advisory, and lies close to the GFEX and TVCN consensus models. Danny is expected to remain a sheared tropical cyclone or low until dissipation occurs. In the short term, however, there could be some minor fluctuations in intensity today as the deep-layer southwesterly vertical wind shear decreases some before increasing again and becoming stronger by Tuesday morning. Mid-level dry air with humidity values decreasing to less than 40 percent should also enhance the weakening process. As result, Danny is expected to become a tropical depression by this evening, degenerate into a remnant low on Tuesday, and dissipate by Wednesday. The NHC intensity forecast is similar to the previous advisory and the ICON intensity consensus model. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 15.8N 60.5W 35 KT 40 MPH 12H 24/1800Z 16.1N 62.6W 30 KT 35 MPH 24H 25/0600Z 16.5N 65.2W 30 KT 35 MPH 36H 25/1800Z 17.0N 67.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 26/0600Z 17.4N 71.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 27/0600Z...DISSIPATED $$ Forecaster Stewart |