332 
 WTPA42 PHFO 190247
 TCDCP2
  
 Hurricane Lane Discussion Number  17
 NWS Central Pacific Hurricane Center Honolulu HI   EP142018
 500 PM HST Sat Aug 18 2018
  
 Lane's satellite presentation has degraded a bit over the past few
 hours, with the eye clouding over and cooling. The central
 convective ring has become a bit asymmetric, becoming elongated
 east-to west roughly along the axis of 15 to 18 kt vertical shear.
 Outflow seems more favorable now to the east-northeast than 6 to 12
 hours ago. Nevertheless, Lane remains a powerful hurricane, with
 objective Dvorak Current Intensity (CI) numbers between 6.0/115 kt
 (JTWC/SAB) and 6.5/127 kt (PHFO). ADT from UW-CIMSS is weaker at
 5.0/105 kt. The initial intensity is set at 115 kt for this
 advisory, based on a mix of these estimates. 
 
 Lane continues moving toward the west-northwest at about 14 kt,
 representing a slight increase in forward speed. This system
 should continue on this track through 24 hours, driven by a large
 subtropical ridge to its north. As the ridge builds westward, Lane
 should shift to a more westerly track from 24 through 72 hours. A
 shift back toward the west-northwest should occur from 96 through
 120 hours as Lane approaches the western portion of the ridge.
 Track guidance remains rather tight, depicting a gradual decrease
 in forward speed through the forecast period. The first few
 forecast points were pushed forward slightly to account for the
 small bump in initial forward speed, but the overall forecast track
 closely resembles the previous one, neatly following TVCE consensus.
 
 The intensity forecast roughly follows IVCN consensus guidance,
 depicting a gradual weakening through 120 hours. SSTs will remain
 in the 27 to 28 degree C range, but with 10 to 15 kt of vertical
 shear expected through the forecast period, a forecast for gradual
 weakening seems sound. 
 
 Lane is forecast to pass south of the main Hawaiian Islands
 Wednesday and Thursday, potentially causing local impacts as it
 tracks west northwestward. Interests in those islands should watch
 the progress of Lane closely, since day 4 and 5 forecast track
 errors can be large. 
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  19/0300Z 12.8N 141.0W  115 KT 130 MPH
  12H  19/1200Z 13.2N 143.0W  105 KT 120 MPH
  24H  20/0000Z 13.5N 145.2W  100 KT 115 MPH
  36H  20/1200Z 13.7N 147.1W   95 KT 110 MPH
  48H  21/0000Z 13.9N 148.9W   90 KT 105 MPH
  72H  22/0000Z 14.2N 152.2W   80 KT  90 MPH
  96H  23/0000Z 15.0N 155.7W   65 KT  75 MPH
 120H  24/0000Z 16.2N 159.2W   55 KT  65 MPH
  
 $$
 Forecaster Powell