ZCZC MIATCDAT5 ALL TTAA00 KNHC DDHHMM HURRICANE NICOLE DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 500 PM AST THU OCT 06 2016 Nicole's cloud pattern has continued to increase in organization this afternoon. A small central dense overcast has become even more symmetric during the last few hours, with an eye intermittently visible. Dvorak classifications of T4.5 from TAFB and UW-CIMSS ADT values support increasing the intensity to 75 kt. Nicole is being affected by northerly shear associated with outflow of Hurricane Matthew, but it is suspected that this shear is confined to a narrow layer at upper levels since the cyclone has been unexpectedly strengthening. Given the current trends, additional intensification seems possible, at least during the short term. However, a mid- to upper-level trough digging over the central Atlantic should cause the shear over Nicole to greatly increase in 1 to 2 days and result in some weakening. There could also be some interaction of Nicole with a piece of the trough that breaks off in 2 to 3 days, as shown in the global models, but it is unclear how this could affect its intensity. The large-scale environment is forecast to potentially become more conducive for re- intensification by days 4 or 5, and some restrengthening is shown around that time. The new intensity forecast is above the multi-model consensus and higher than the previous one at the end of the forecast period. The initial motion estimate is 330/06. Steering currents are likely to collapse very soon as Nicole finds itself in a col area, making an erratic northward motion likely for the next 12 hours or so. A blocking ridge in the wake of the aforementioned trough should then impart a slow southerly motion for a couple of days. By 72 hours, a turn back toward the northwest or north-northwest is forecast as a mid-level high builds to the east of Nicole. Although there is considerable spread in the model guidance, this general scenario is shown except for the ECMWF, which is well to the right of the other model solutions through the next 3 days. The new track forecast is of low confidence, is faster than the previous one, and is between the previous forecast and an average of the ECMWF/GFS output. Swells associated with this slow-moving storm are affecting Bermuda, and these conditions are likely to continue for the next several days. FORECAST POSITIONS AND MAX WINDS INIT 06/2100Z 27.5N 65.1W 75 KT 85 MPH 12H 07/0600Z 27.9N 65.3W 85 KT 100 MPH 24H 07/1800Z 27.6N 65.2W 80 KT 90 MPH 36H 08/0600Z 27.0N 64.9W 75 KT 85 MPH 48H 08/1800Z 26.5N 64.6W 70 KT 80 MPH 72H 09/1800Z 26.4N 65.3W 60 KT 70 MPH 96H 10/1800Z 27.4N 66.7W 60 KT 70 MPH 120H 11/1800Z 29.4N 67.7W 65 KT 75 MPH $$ Forecaster Kimberlain NNNN