ZCZC HFOTCDCP1 ALL TTAA00 PHFO DDHHMM Hurricane Hector Discussion Number 37 NWS Central Pacific Hurricane Center Honolulu HI EP102018 500 AM HST Thu Aug 09 2018 The eye of Hector warmed and become much better defined in infrared satellite imagery overnight. As a result, the satellite fix agencies provided subjective Dvorak satellite-based intensity estimates of near 102 kt. The latest ADT estimate from UW-CIMSS is near 105 kt. Based on the improved appearance of the hurricane, we have increased the initial intensity to 105 kt for this advisory. Hector has been traveling nearly due west early this morning, so the latest motion is 270/14 kt. Hector is expected to continue moving westward along the southern periphery of a strong mid-level ridge located north of the main Hawaiian Islands. This ridge is forecast to move little during the next day or two. Hector is expected to gradually turn toward the west-northwest in 24-36 hours as it reaches the southwestern periphery of the ridge. After that, a gradual turn toward the northwest is possible during 48-72 hours. The latest track forecast lies close to the previous forecast and a tightly-packed guidance envelope through day 3. Increased guidance spread on days 4 and 5 arises due to differences in the forecast strength and position of the ridge, and a developing low aloft to the northwest of Hector. The latest forecast adjusts the track slightly to the right of the previous forecast. This is based on the latest consensus guidance, including the TVCN and GFEX, as well as the HWRF. Since Hector has strengthened slightly overnight, we see no obvious impediments to it maintaining about the same intensity during the next 36 hours. The ICON, SHIPS, and HWRF seem to agree with this scenario. After that, some gradual weakening is possible from days 2 through 5 as it starts to encounter cooler water temperatures and increasing southwesterly shear. A Tropical Storm Watch has been issued for Johnston Island. If the expected turn toward the west-northwest does not occur, tropical storm conditions are possible there starting late Friday. Elsewhere, interests in the Northwestern Hawaiian Islands, including Midway and Kure Atolls and the Papahanaumokuakea Marine National Monument west of Pearl/Hermes, should monitor the progress of Hector. Note, this does not include the main Hawaiian Islands. FORECAST POSITIONS AND MAX WINDS INIT 09/1500Z 16.6N 160.1W 105 KT 120 MPH 12H 10/0000Z 16.8N 162.2W 105 KT 120 MPH 24H 10/1200Z 17.2N 164.9W 105 KT 120 MPH 36H 11/0000Z 17.9N 167.5W 105 KT 120 MPH 48H 11/1200Z 18.9N 169.9W 100 KT 115 MPH 72H 12/1200Z 21.5N 174.0W 90 KT 105 MPH 96H 13/1200Z 25.0N 179.0W 80 KT 90 MPH 120H 14/1200Z 28.5N 176.0E 65 KT 75 MPH $$ Forecaster Houston NNNN