Hurricane Hector Discussion Number 22
Wiki-Hurricanes Forecast Center
2:00 AM PDT Mon Aug 6 2018
Hector remains a powerful Category 4 hurricane as it enters the Central Pacific this morning. The system has maintained a distinct eye encapsulated by a symmetrical and intense central dense overcast. The extent of the deepest convection has actually increased since the previous advisory, but the eye has also shrunk and cooled. This suggests that Hector may be at the onset of another eyewall replacement cycle in the short term. Satellite intensity estimates were a consensus T6.0/115kt from SAB and TAFB; UW-CIMSS ADT, meanwhile, has decreased some to T6.2/119.8kt. Given ongoing trends and a blend of recent estimates, the initial intensity is lowered slightly to 115kt.
There have been no high quality microwave passes for over 12 hours, which makes assessing the internal structure of Hector difficult. However, given the shrinking eye and general appearance of the deepest convection--focused in two different bands west of the center--an eyewall replacement cycle appears imminent. This should result in some weakening of Hector in the immediate future. Additionally, the hurricane will be traversing sea surface temperatures cooler than 27C over the next 48 hours. To yield solace to Hector, its annular characteristics should keep the weakening trend more tame than it would be for an average tropical cyclone. By days 4 and 5, with warming ocean temperatures and a continued low shear environment, reintensification is expected.
Hector continues its west-northwest trajectory, toward a weakness in the mid-level ridge to its north. This ridge should intensify tomorrow, forcing Hector to the west and south of the Hawaiian Islands, where a direct hit is not expected but fringe effects are anticipated. Around day 5, Hector should reach the western periphery of the mid-level ridge to its north and resume a west-northwest motion toward the International Date Line.
FORECAST POSITIONS AND MAX WINDS
INIT 06/0300Z 115 KT 130 MPH
12H 06/1200Z 105 KT 120 MPH
24H 07/0000Z 100 KT 115 MPH
36H 07/1200Z 95 KT 110 MPH
48H 08/0000Z 90 KT 105 MPH
72H 09/0000Z 90 KT 105 MPH...CLOSEST APPROACH TO HAWAII
96H 10/0000Z 95 KT 110 MPH
120H 11/0000Z 100 KT 115 MPH