058 WTPZ45 KNHC 050239 TCDEP5 Hurricane Hector Discussion Number 18 NWS National Hurricane Center Miami FL EP102018 800 PM PDT Sat Aug 04 2018 Hector has the textbook appearance of a major hurricane in satellite imagery this evening, as it is maintaining a well-defined 10 nm wide eye inside a central dense overcast. Satellite intensity estimates are mostly near 115 kt, and based on these estimates that will be the initial intensity for this advisory. The most notable change since the last advisory has been an increase in convection in an outer band that now mostly surrounds the CDO. The initial motion is 275/10. There is little change to the forecast philosophy from the previous advisory. A large subtropical ridge to the north should steer the hurricane generally westward through the forecast period, with Hector gradually gaining some latitude on Sunday and beyond due to a weakness in the ridge. By 72-96 h, most of the guidance shows a more westward motion south of the Hawaiian Islands. Based on slight shifts in the consensus models, the new forecast track is nudged a little to the north of the previous track through 72 h, and it is similar to the previous track after that time. It should be noted that there remains some spread in the dynamical models as Hector approaches Hawaii, with the NAVGEM, HWRF, and GFS to the north of the center of the guidance envelope and the ECMWF to the south. The recent increase in outer band convection decreases the short- term chance that Hector will become an annular hurricane. However, the cyclone will be in the light-shear moderate-SST conditions favorable for such an evolution, and it could occur later in the forecast period. Before this, it is likely that Hector will undergo another eyewall replacement with associated fluctuations in intensity. After 36-48 h, the hurricane should start to encounter a drier airmass and slowly weaken in consequence. The new NHC intensity forecast is unchanged from the previous one, and it lies at the upper end of the intensity guidance. While the official forecast track continues to lie south of the Hawaiian Islands, it is too soon to determine what kind of impacts might occur in the state, since track errors can be large at long time ranges. This remains a good time for everyone in the Hawaiian Islands to ensure they have their hurricane plan in place. For additional information on any potential local impacts from Hector in Hawaii, please refer to products issued by the NWS Weather Forecast Office in Honolulu at http://www.prh.noaa.gov/hnl . FORECAST POSITIONS AND MAX WINDS INIT 05/0300Z 14.3N 134.7W 115 KT 130 MPH 12H 05/1200Z 14.5N 136.3W 115 KT 130 MPH 24H 06/0000Z 14.8N 138.7W 115 KT 130 MPH 36H 06/1200Z 15.3N 141.3W 115 KT 130 MPH 48H 07/0000Z 15.8N 144.2W 110 KT 125 MPH 72H 08/0000Z 16.5N 150.5W 100 KT 115 MPH 96H 09/0000Z 17.0N 156.0W 90 KT 105 MPH 120H 10/0000Z 17.5N 161.5W 85 KT 100 MPH $$ Forecaster Beven