ZCZC MIATCDAT5 ALL TTAA00 KNHC DDHHMM TROPICAL STORM NICOLE DISCUSSION NUMBER 18 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 1100 AM AST SAT OCT 08 2016 Nicole's cloud pattern has further deteriorated this morning. The low-level center has been exposed, with generally only shallow convection on the southern and eastern periphery of the cyclone's circulation. A new burst of deeper convection has developed southeast of the center in the last couple of hours, however. Dvorak Final-T numbers continue to decrease, and a blend of those data and CI-numbers support lowering the initial intensity estimate to 35 kt. Nicole is moving just west of due south or 190/06. A blocking high north of the cyclone should continue to push it southward for about 24 hours. Nicole should then reverse its heading and turn north- northwestward, when the mid-level high shifts to its northeast. A potential complication to the track forecast is the degree to which Nicole interacts with Matthew or its remnants, beginning in 2 to 3 days through the latter part of the forecast period. The ECMWF shows a stronger binary interaction and draws Nicole much farther west than the GFS after 72 hours, and the differences in the models by 96 hours become extreme. The track forecast philosophy continues to closely follow a blend of the ECMWF and GFS model solutions, though slightly more weight has been placed on the GFS-based guidance since a sizable number of ECMWF ensemble members are east of its deterministic run. Admittedly, the forecast on days 4 and 5 are of low confidence. The shear is forecast to be so strong in the short term that one might be tempted to call for Nicole to degenerate to a remnant low, especially given its current satellite appearance. However, the shear is forecast to nominally decrease, when the tail of a mid- to upper-level trough over the central Atlantic fractures and becomes co-located with the tropical cyclone during the next day or so. How the merger of the two affects Nicole's intensity and structure remains unclear. Nonetheless, the large-scale conditions are shown to become less hostile in 2 to 4 days, and it seems plausible that some re-intensification of the cyclone could occur before becoming less favorable again by day 5. The new intensity forecast is somewhat lower than the previous one and below the multi-model consensus, and continues to show a modest recovery after 72 hours. The intensity forecast continues to be of low confidence in the long range. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 25.2N 65.7W 35 KT 40 MPH 12H 09/0000Z 24.6N 65.7W 35 KT 40 MPH 24H 09/1200Z 24.2N 65.8W 35 KT 40 MPH 36H 10/0000Z 24.8N 65.9W 35 KT 40 MPH 48H 10/1200Z 25.7N 66.0W 35 KT 40 MPH 72H 11/1200Z 28.3N 66.6W 40 KT 45 MPH 96H 12/1200Z 30.5N 67.0W 45 KT 50 MPH 120H 13/1200Z 33.4N 64.6W 45 KT 50 MPH $$ Forecaster Kimberlain NNNN