944 
 WTPA42 PHFO 230857
 TCDCP2
  
 Hurricane Lane Discussion Number  35
 NWS Central Pacific Hurricane Center Honolulu HI   EP142018
 1100 PM HST Wed Aug 22 2018
  
 Lane remains resilient in the face of increasing southwesterly 
 wind shear, and remains a potent category 4 hurricane this evening. 
 The cloud-filled eye continues to be surrounded by a solid ring of 
 cold cloud tops, with lightning bursts persisting in the northern 
 eye wall for the last several hours. The subjective Dvorak current 
 intensity estimates from GTW/TAFB/HFO/SAB were all 6.5/127 kt for 
 this advisory, while ADT was slightly lower. The current intensity 
 estimate for this advisory will remain 125 kt based on a blend of 
 these data. 
 
 Lane continues to make the long-awaited turn toward the northwest, 
 and the forward speed has slowed, with the initial motion for 
 this advisory estimated to be 315/6 kt. Lane has reached the
 western periphery of a deep-layer ridge, with a trough aloft to the 
 northwest of Hawaii. The steering flow is relatively light and out 
 of the south, and Lane will move northwest and north at a
 relatively slow speed through Friday in this environment. By 48 to
 72 hours, most of the track guidance begins to show a sharp turn
 toward the west, as the low level circulation of Lane decouples in
 the face of 35 to 40 kt of shear. Exactly when this critical turn
 will happen is very difficult to forecast, so confidence in this
 portion of the track is quite low. The updated track forecast is
 very close to the previous but has been shifted slightly closer to
 the islands on days 2 and 3, when Lane will be making its closest
 point of approach to the islands. In deference to the HCCA,
 the forecast track has shifted to the right in response to the
 HWFI/GFSI and other members doing so, while the EMXI lies on the
 left hand side of the guidance envelope. Beyond 72 hours, the
 shallow circulation of Lane is expected to be carried westward away
 from the islands in the low-level trade wind flow. 
 
 Lane is beginning to move underneath increasing shear, analyzed to 
 be near 20 kt, and latest satellite pictures indicate that this may 
 be finally beginning to negatively impact Lane. The shear is 
 expected to remain moderate for the first 24 to 36 hours, then 
 become quite strong beyond 48 hours. A gradual weakening trend is 
 shown through 48 hours, with more rapid weakening beyond that time 
 frame. The intensity forecast remains on the high end of the 
 guidance envelope, but follows closely all of the guidance trends 
 that indicate significant weakening through the forecast period. 
 
 KEY MESSAGES: 
 
 1. Lane will pass dangerously close to the main Hawaiian Islands as 
 a hurricane Thursday and Friday, and is expected to bring damaging 
 winds. These winds can be accelerated over and downslope from
 elevated terrain, and will be higher in high rise buildings.
 
 2. The slow movement of Lane also greatly increases the threat for 
 prolonged heavy rainfall and extreme rainfall totals. This is 
 expected to lead to life-threatening flash flooding and landslides 
 over all Hawaiian Islands. 
 
 3. Large and damaging surf can be expected along exposed
 shorelines, especially along south and west facing coasts, with
 localized storm surge exacerbating the impacts of a prolonged period
 of damaging surf.
  
 4. Do not focus on the exact forecast track or intensity of Lane, 
 and be prepared for adjustments to the forecast. Although the 
 official forecast does not explicitly indicate Lane's center making 
 landfall over any of the islands, this could still occur. Even if 
 the center of Lane remains offshore, severe impacts could still be 
 realized as they extend well away from the center. 
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  23/0900Z 16.3N 156.9W  125 KT 145 MPH
  12H  23/1800Z 17.2N 157.2W  120 KT 140 MPH
  24H  24/0600Z 18.4N 157.4W  115 KT 130 MPH
  36H  24/1800Z 19.5N 157.6W   95 KT 110 MPH
  48H  25/0600Z 20.2N 158.1W   75 KT  85 MPH
  72H  26/0600Z 20.4N 160.5W   65 KT  75 MPH
  96H  27/0600Z 20.0N 163.0W   50 KT  60 MPH
 120H  28/0600Z 20.5N 166.5W   40 KT  45 MPH
  
 $$
 Forecaster Birchard