ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM TROPICAL STORM HENRI DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL082015 1100 AM AST FRI SEP 11 2015 Visible satellite images indicate that the surface circulation of Henri has become rather distorted this morning. Multiple low-level swirls can be seen in the circulation that is elongated from southeast to northwest, with some suggestion that the cyclone may no longer be closed in the northwestern quadrant. The intensity is being held at 35 kt in agreement with the satellite estimate from TAFB. Although shear is somewhat lower over the cyclone, it appears that the low-level structure is too poor to take advantage of the more favorable environment. The intensity forecast has been lowered a little to reflect the less conducive conditions. The cyclone or its remnants are forecast to undergo extratropical transition in about 24 hours while moving over colder water with high shear, and the system is likely to be absorbed by a larger extratropical cyclone by 72 hours. An alternate scenario, one that is becoming more likely, is that Henri could degenerate into a trough later today. The initial motion estimate is 020/17. Henri is expected to accelerate north-northeastward and then northeastward during the next day or so as it encounters increasing flow ahead of a deep longwave trough digging into eastern North America and the western Atlantic. The post-tropical cyclone or its remnants should then turn east-northeastward over the north Atlantic. The new track forecast is very similar to the previous one and near or on the right side of the model consensus. FORECAST POSITIONS AND MAX WINDS INIT 11/1500Z 38.0N 59.4W 35 KT 40 MPH 12H 12/0000Z 41.0N 57.7W 35 KT 40 MPH 24H 12/1200Z 44.9N 54.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 36H 13/0000Z 48.0N 48.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 48H 13/1200Z 50.0N 42.0W 30 KT 35 MPH...POST-TROP/EXTRATROP 72H 14/1200Z...DISSIPATED $$ Forecaster Blake NNNN