Show Selection: |
#875062 (Received by flhurricane at: 11:01 AM 16.Sep.2016) TCDAT2 TROPICAL STORM KARL DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 1100 AM AST FRI SEP 16 2016 Karl remains a sheared tropical cyclone this morning with all of its deep convection in the northeastern quadrant due to shear related to its interaction with a mid- to upper-level trough. The initial wind speed is kept at 40 kt for this advisory, a compromise between lower Dvorak estimates and higher, but noisy, scatterometer values. Vertical shear is expected to decrease in about 36 hours, and, despite a somewhat dry environment, warming sea surface temperatures should allow for at least gradual strengthening. The intensity models continue to trend higher at the end of the forecast period, and the official forecast follows this trend. This forecast is remains close to the SHIPS and LGEM models. The center of Karl has become a little distorted due to the shear and convection, but it still seems to be moving about 280/11. Karl is forecast to turn more to the west and south-of-west this weekend as the subtropical ridge strengthens to the north of the cyclone. However, the current interaction of Karl with the mid- to upper-level trough has not been well forecast, and Karl probably will not get as far to the south as expected yesterday. In a few days, the storm should move to the west-northwest and eventually more to northwest around day 5 as it reaches the edge of the ridge. The new forecast is close to a blend of the ECMWF and GFS, plus their respective ensemble means, ending up a little north of the previous NHC prediction at long range. FORECAST POSITIONS AND MAX WINDS INIT 16/1500Z 18.4N 34.3W 40 KT 45 MPH 12H 17/0000Z 18.5N 36.2W 40 KT 45 MPH 24H 17/1200Z 18.4N 38.8W 40 KT 45 MPH 36H 18/0000Z 17.9N 41.5W 40 KT 45 MPH 48H 18/1200Z 17.7N 44.0W 45 KT 50 MPH 72H 19/1200Z 18.3N 49.0W 50 KT 60 MPH 96H 20/1200Z 20.0N 54.0W 60 KT 70 MPH 120H 21/1200Z 22.5N 58.5W 70 KT 80 MPH $$ Forecaster Blake |