528 WTPZ43 KNHC 092037 TCDEP3 Tropical Storm Kristy Discussion Number 12 NWS National Hurricane Center Miami FL EP132018 200 PM PDT Thu Aug 09 2018 Kristy's deep convection has been waxing and waning, with an overall decrease a few hours ago followed by a recent increase near the center. The advisory intensity is kept at 55 kt, in agreement with objective ADT values from UW/CIMSS and a subjective Dvorak classification from TAFB. Kristy is over marginally warm waters, in low vertical shear, and with fairly well-defined upper-level outflow. There is a window of opportunity of about a day for additional intensification, and the official intensity forecast follows the intensity model consensus and the LGEM guidance. A weakening trend is likely to commence by Friday night, and Kristy should degenerate into a post-tropical cyclone by late in the weekend. Visible imagery and some microwave data provided more accurate center fixes than earlier today, and the initial motion is a more confident 360/6 kt. The main steering mechanisms for Kristy are a weak ridge to the north and the large circulation of weakening John to the northeast. There continues to be significant diversity in the track models. The ECMWF and UKMET models, and their ensembles, are substantially to the left of the other guidance with the GFS, HWRF, and HMON much more to north and east, presumably due to interaction with John. Since the weakening John may not be that much of an influence, the official forecast is roughly in the middle of these two extremes and close to the model consensus. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 16.9N 130.1W 55 KT 65 MPH 12H 10/0600Z 17.7N 129.8W 60 KT 70 MPH 24H 10/1800Z 19.0N 129.1W 60 KT 70 MPH 36H 11/0600Z 20.3N 128.7W 55 KT 65 MPH 48H 11/1800Z 21.3N 128.6W 50 KT 60 MPH 72H 12/1800Z 23.0N 129.0W 35 KT 40 MPH...POST-TROPICAL 96H 13/1800Z 25.0N 130.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 14/1800Z 27.0N 131.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Pasch