ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM TROPICAL STORM IVETTE DISCUSSION NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102016 200 AM PDT SAT AUG 06 2016 Ivette is feeling the effects of 10-15 kt of southwesterly vertical shear and dry air entrainment, as conventional and microwave satellite imagery indicate that the low-level center is now displaced to the southwest of the convection. The initial intensity remains 50 kt in agreement with various subjective and objective satellite intensity estimates. However, this could be a little generous. The initial motion is 280/9, as the storm continues to be steered by the subtropical ridge to its north. Ivette should turn toward the west-northwestward shortly, as it nears the western periphery of the ridge. However, in about three days, the tropical cyclone should turn westward as the weakening system is steered by the low-level easterly trade winds. The new track forecast is little changed from the previous forecast and lies near the TVCN consensus model. Although Ivette is expected to remain over 26C-28C sea surface temperatures during the forecast period, the combination of increasing shear and abundant dry air seen in water vapor imagery are expected to cause the storm to weaken. The intensity forecast no longer shows any intensification. Instead, the initial intensity is maintained through 24 hours in general agreement with the intensity guidance, followed by a slow weakening trend. The dynamical models are in good agreement that Ivette will weaken to a trough by 120 hours, so the forecast calls for the cyclone to dissipate by that time. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 15.8N 133.6W 50 KT 60 MPH 12H 06/1800Z 16.2N 135.0W 50 KT 60 MPH 24H 07/0600Z 16.9N 136.8W 50 KT 60 MPH 36H 07/1800Z 17.7N 138.4W 45 KT 50 MPH 48H 08/0600Z 18.3N 139.9W 40 KT 45 MPH 72H 09/0600Z 18.5N 143.0W 30 KT 35 MPH 96H 10/0600Z 18.0N 147.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 11/0600Z...DISSIPATED $$ Forecaster Beven NNNN