858 
 WTPZ44 KNHC 161456
 TCDEP4
 
 Tropical Storm Lane Discussion Number   7
 NWS National Hurricane Center Miami FL       EP142018
 800 AM PDT Thu Aug 16 2018
 
 Lane appears to be intensifying this morning, with a more symmetric
 presentation on satellite imagery and pulsing deep convection near
 the center.  A recent SSMI/S microwave pass indicates that an inner
 core is trying to form, although it isn't well defined yet. The
 current intensity estimates continue to display a large spread,
 ranging from the overnight scatterometer data at low-end tropical-
 storm strength, from hurricane strength in the TAFB Dvorak estimate.
 The initial wind speed is set to 50 kt with the increased
 organization, and this remains a low confidence estimate.
 
 While so far Lane has only been slowly intensifying, the large-scale
 environment appears favorable for more significant intensification
 to occur soon, especially with current signs of a primitive inner
 core. Thus the wind speed forecast will maintain the quick
 strengthening from the previous forecast, and there remains a
 significant chance that rapid intensification will occur during the
 next few days.  The biggest change from yesterday is that more of
 the global models are indicating that westerly shear could affect
 Lane in the central Pacific, so more weakening is shown at day 5.
 Otherwise, the new NHC intensity forecast is very close to the
 previous one and is on the higher side of the guidance.
 
 The initial motion estimate is 275/11.  The subtropical ridge to
 the north of Lane should continue to be the dominant steering
 mechanism, forcing the tropical cyclone to move westward or
 west-northwestward for the next several days.  While the model
 spread is low in the short range, it notably increases by days 4/5.
 The GFS-based guidance is showing Lane move slower than the rest of
 the guidance, which allows the eastern periphery of the ridge to
 erode due to an inverted mid-level trough, and consequently a more
 poleward motion of the cyclone.  The ECMWF and UKMET show Lane
 moving faster and basically missing any influence of that trough,
 causing the storm to move faster to the west.  There are no
 strong signals pointing me to either solution, so the official
 forecast follows the trend of the consensus, which ends up slightly
 west of the previous forecast.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  16/1500Z 10.6N 127.6W   50 KT  60 MPH
  12H  17/0000Z 10.8N 129.4W   60 KT  70 MPH
  24H  17/1200Z 11.2N 132.1W   75 KT  85 MPH
  36H  18/0000Z 11.7N 134.9W   85 KT 100 MPH
  48H  18/1200Z 12.2N 137.6W   95 KT 110 MPH
  72H  19/1200Z 13.5N 142.7W  105 KT 120 MPH
  96H  20/1200Z 14.7N 147.3W  105 KT 120 MPH
 120H  21/1200Z 15.3N 151.5W   95 KT 110 MPH
 
 $$
 Forecaster Blake