Hurricane Hector Discussion Number 13
Wiki-Hurricanes Forecast Center
2:00 PM PDT Fri Aug 3 2018
Hector's fluctuations continue this afternoon as it appears to be reorganizing back from this morning's core decay. The central dense overcast has slowly become more symmetric, and while the eye has not become particularly pronounced in infrared channels, the hurricane has made a more appreciable attempt to establish central clearing, and latest imagery shows a distinct and small pinhole eye. The eye is now more evident in visible imagery compared to sunrise. The storm's moisture transport has improved and has become more established, suggesting that the system's circulation has regained composure. SAB provided an aggressive CI value of T5.5/102kt with other Dvorak parameters at T5.0/90kt. TAFB estimated T5.0/90kt, while UW-CIMSS ADT has observed T5.1/92kt raw values when set to an eye scene type. Based on fair consensus among these estimates, the current intensity for Hector has been raised to 90 kt.
No changes to the overall steering forecast for Hector with the broad 594 dm high pressure area centered southwest of California still in place. A west-northwesterly curved path should begin in around two days and continue out to five days, though the bearing during that time should gradually trend towards a more direct 270 degree westerly trajectory. Hector is on a restrengthening trend which should continue out to at least 48 hours given conditions which are supportive of development. SHIPS and LGEM have both dropped their earlier indications of a gradual long-term weakening trend and now reflect an increase in strength during this timeframe. There have not been many other significant changes to observed or modeled environmental conditions, and model guidance from late-cycle 12z and early-cycle 18z suites show more or less the same as they did earlier. Should the system acquire annular characteristics, which could occur on day 2 or day 3, the storm's peak strength could hold out for longer than a traditional tropical cyclone. Still, by day 5, conditions near Hawaii will have dried sufficiently enough where they would tampen any tropical cyclone, with SHIPS diagnostic outputs indicating relative humidity values as low as 41%. Marginal instability during that would also favor convective loss. The storm's peak intensity has been carried over from previous advisories, with end-of-run weakening indicated.
FORECAST POSITIONS AND MAX WINDS
INIT 03/2100Z 90 KT 105 MPH
12H 04/0600Z 100 KT 115 MPH
24H 04/1800Z 110 KT 125 MPH
36H 05/0600Z 115 KT 130 MPH
48H 05/1800Z 115 KT 130 MPH
72H 06/1800Z 110 KT 125 MPH
96H 07/1800Z 100 KT 115 MPH
120H 08/1800Z 85 KT 100 MPH