810 
 WTPZ42 KNHC 191435
 TCDEP2
 
 TROPICAL STORM KAY DISCUSSION NUMBER   4
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP122016
 900 AM MDT FRI AUG 19 2016
 
 Shortwave infrared imagery and a 0850 UTC AMSR2 microwave image
 show that Kay's center of circulation continues to be sheared
 to the northeast of the deep convection.  The coldest cloud tops
 are confined to a curved band wrapping in toward the center from the
 southern half of the system.  The initial intensity remains at 35
 kt and is based on a consensus of Final-T number (T2.5) satellite
 intensity estimates from TAFB and SAB.  Global models and the SHIPS
 guidance indicate that the shear should relax within the next 24
 hours.  Therefore, some strengthening is expected through day 2.
 For the remaining portion of the forecast, Kay should gradually
 weaken as it moves into a more stable thermodynamic environment and
 over cooler sea surface temperatures of around 25C.  The large-scale
 models are also showing increasing upper-level easterlies at that
 time.  The NHC intensity forecast is based on the IVCN consensus and
 reflects Kay degenerating into a remnant low in 96 hours.
 
 The initial motion is a little uncertain, but based on the
 earlier microwave images and surface observations from Socorro
 Island, Kay appears to be moving at 320/7 kt.  The Socorro Island
 observations during the past few hours indicate that the center of
 Kay is passing very close to the island.  The cyclone should move
 northwestward around the western portion of a mid- to upper-level
 tropospheric ridge over northwestern Mexico during the next couple
 of days.  The GFS and its ensemble mean have shifted considerably
 toward the left, closer to the other global and regional guidance,
 and consequently, have reduced the earlier noted large model spread.
 Beyond day 3, Kay is forecast to turn slowly toward the
 west-northwest in response to the low-level tradewind flow steering
 the shallow remnant low.  The official forecast is close to the TVCN
 consensus and is slightly faster than the previous advisory beyond
 the 48 hour period due primarily to the significant shift in the
 GFS.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  19/1500Z 19.1N 111.5W   35 KT  40 MPH
  12H  20/0000Z 19.7N 112.0W   40 KT  45 MPH
  24H  20/1200Z 20.5N 112.6W   40 KT  45 MPH
  36H  21/0000Z 21.0N 113.0W   40 KT  45 MPH
  48H  21/1200Z 21.6N 113.6W   35 KT  40 MPH
  72H  22/1200Z 22.2N 114.7W   30 KT  35 MPH
  96H  23/1200Z 23.0N 116.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 120H  24/1200Z 23.7N 118.9W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
 $$
 Forecaster Roberts