000 WTPZ41 KNHC 140237 TCDEP1 Hurricane Fernanda Discussion Number 9 NWS National Hurricane Center Miami FL EP062017 800 PM PDT Thu Jul 13 2017 Fernanda continues to strengthen. Although there has been no hint of an eye in geostationary satellite imagery, the center is embedded within a symmetric CDO and a recent SSMIS overpass revealed a small banded eye. The upper-level outflow is well established over the eastern and southern semicircles but there is some evidence of a little northerly shear beneath the high cirrus layer that may have temporarily slowed the intensification process. Subjective and objective Dvorak T-numbers range from T4.0 to T4.6, which yields an initial intensity estimate of 75 kt. The upper-level pattern over the cyclone is forecast to become ideal for strengthening with the shear remaining quite low throughout the forecast period. As a result, significant strengthening is forecast while the hurricane moves over SSTs of 28-29 deg C during the next couple of days. The SHIPS Rapid Intensification Index is still indicating a notable chance of RI over the next 24 hours, and the NHC foreast once again calls for rapid strengthening during the next 24 to 36 hours. After that time, eyewall replacement cycles could cause some fluctuations in intensity. In about 72 hours, the hurricane is expected to begin moving over cooler water which should result in weakening late in the period. Recent satellite fixes show that Fernanda is moving slightly south of west or 260/10 kt. A deep-layer ridge to the north of the cyclone is expected to keep the hurricane on a general westward heading during the next day or so. After that time, a mid- to upper-level trough to the northeast of the Hawaiian Islands is expected to cause the western portion of the ridge to weaken. This should cause Fernanda to turn west-northwestward over the weekend. The track guidance is in very good agreement, and the new NHC track is essentially an update of the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 14/0300Z 11.0N 117.0W 75 KT 85 MPH 12H 14/1200Z 10.9N 118.3W 90 KT 105 MPH 24H 15/0000Z 10.8N 120.2W 105 KT 120 MPH 36H 15/1200Z 11.1N 122.3W 115 KT 130 MPH 48H 16/0000Z 11.7N 124.6W 120 KT 140 MPH 72H 17/0000Z 13.0N 129.2W 120 KT 140 MPH 96H 18/0000Z 14.4N 133.2W 105 KT 120 MPH 120H 19/0000Z 15.8N 137.0W 85 KT 100 MPH $$ Forecaster Brown