000 WTPZ41 KNHC 122039 TCDEP1 Tropical Storm Fernanda Discussion Number 4 NWS National Hurricane Center Miami FL EP062017 300 PM MDT Wed Jul 12 2017 Fernanda has changed little in organization since the last advisory, as the center continues to be near the northeastern edge of the central convection and outer bands persist in the southwestern semicircle. Recent scatterometer data indicated maximum winds near 35 kt, and that remains the initial intensity based on the scatterometer and various satellite intensity estimates. The scatterometer data also showed the Fernanda is currently a small cyclone, with tropical-storm-force winds extending no more than 20 n mi from the center. The initial motion is now 265/8. Deep-layer ridging north of the cyclone is steering it a little south of due west, and the ridge is expected to strengthen and build westward during the next several days. Thus, a westward or south of westward motion is likely for the first 72 h. After that, Fernanda should approach a weakness in the ridge caused by a mid- to upper-level trough over the central Pacific, and in response it is expected to turn west-northwestward by 120 h. The new forecast track is again similar to, but a little south of the previous track. It lies a little north of the consensus models through 72 h and south of them at 96-120 h. The cyclone is still feeling the effects of 10-15 kt of vertical wind shear at this time. The large-scale models continue to forecast the shear to subside over the next 24 h or so and then remain light through the remainder of the forecast period. That, combined with 28-29C sea surface temperatures along the first 96 h of the forecast track, should allow the system to intensify. After 96 h, the expected more northward motion would bring Fernanda over decreasing seas surface temperatures, which would likely stop intensification. The new forecast is again similar to the previous forecast and is in best agreement with the intensity consensus. There remains a possibility that rapid intensification could occur after the shear subsides. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 11.8N 112.2W 35 KT 40 MPH 12H 13/0600Z 11.8N 113.5W 40 KT 45 MPH 24H 13/1800Z 11.7N 115.5W 50 KT 60 MPH 36H 14/0600Z 11.6N 117.5W 60 KT 70 MPH 48H 14/1800Z 11.5N 119.5W 70 KT 80 MPH 72H 15/1800Z 11.5N 124.0W 90 KT 105 MPH 96H 16/1800Z 12.0N 128.5W 95 KT 110 MPH 120H 17/1800Z 13.0N 133.0W 95 KT 110 MPH $$ Forecaster Beven