000 WTPZ42 KNHC 262041 TCDEP2 TROPICAL STORM IGNACIO DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP122015 200 PM PDT WED AUG 26 2015 Ignacio continues to strengthen with plenty of tightly curved bands around the center and an impressive outflow pattern. Dvorak estimates from TAFB/SAB are both 55 kt, and this will be the initial intensity. The environment appears favorable for further intensification with light-to-moderate shear and warm waters for the next several days anticipated. There remains some question as to the amount of vertical shear expected, so it is prudent not to show rapid intensification at this time. Still, the most likely scenario is continued strengthening, which is in line with the latest intensity guidance. The NHC forecast is raised from the previous one and lies above the intensity consensus, just a bit below the Florida State Superensemble. Most of the guidance is showing some weakening at long range due to an increase in shear and less favorable thermodynamic conditions. Scatterometer data indicate the center of Ignacio has continued moving west-southwestward a little longer than anticipated, although recent satellite images suggest a more westward track has started. The current motion estimate is 270/10. A west- northwestward track is likely to start overnight and continue for the next several days while Ignacio is steered around the subtropical ridge. There is considerable uncertainty about the long-range forecast, with the models struggling on how intact the ridge remains to the northeast of Hawaii. On this cycle, the ECMWF and HWRF models have shifted well leftward, dragging the consensus a good bit south of the previous forecast. The official forecast is moved in that direction, although remaining north of the model consensus at day 5. FORECAST POSITIONS AND MAX WINDS INIT 26/2100Z 11.9N 136.2W 55 KT 65 MPH 12H 27/0600Z 12.3N 137.6W 65 KT 75 MPH 24H 27/1800Z 13.2N 139.5W 75 KT 85 MPH 36H 28/0600Z 14.1N 141.4W 85 KT 100 MPH 48H 28/1800Z 15.0N 143.2W 95 KT 110 MPH 72H 29/1800Z 16.5N 146.2W 90 KT 105 MPH 96H 30/1800Z 17.8N 149.4W 85 KT 100 MPH 120H 31/1800Z 19.0N 152.5W 75 KT 85 MPH $$ Forecaster Blake