446 
 WTPZ42 KNHC 221451
 TCDEP2
 
 TROPICAL STORM FRANK DISCUSSION NUMBER   4
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP072016
 900 AM MDT FRI JUL 22 2016
 
 Frank's deep convection is displaying more of a shear pattern this
 morning with a sharp edge to the infrared cloud top temperatures on
 its northeastern side.  All intensity analyses - SAB and TAFB
 Dvorak, ADT, and AMSU - are in good agreement in keeping the
 intensity at 45 kt.  The earlier ASCAT scatterometer pass indicates
 that Frank is a relatively small tropical storm at this time.
 
 Frank should experience moderate to low tropospheric vertical shear,
 warm to hot SSTs, and a moist, unstable atmosphere for the next two
 to three days.  Thus steady intensification is likely.  Beyond day
 three, the tropical cyclone should encounter a more hostile
 environment with cool SSTs to the west of Baja California with a
 more dry, stable atmosphere.  Gradual to steady weakening should
 commence around day three.  The NHC intensity forecast is unchanged
 and is based upon a three member consensus of the LGEM, SHIPS, and
 HWRF models.
 
 A couple timely AMSR2 and SSMIS microwave images were helpful in
 determining the location of Frank's center.  The system is moving
 toward the northwest at about 12 kt, somewhat faster than estimated
 earlier. Frank should turn toward the west-northwest during the next
 few days at a slower rate of forward speed, as the east-west
 extended deep-layer ridge to its north weakens some.  The global
 models and the HWRF hurricane model are in close agreement on this
 scenario and the NHC track prediction has been shifted southward
 between the previous forecast and the consensus mean.
 
 Although the forecast track keeps Frank well removed from Mexico,
 interests in the southern portion of the Baja California peninsula
 should continue to monitor the progress of this cyclone.  As none
 of the GFS, ECWMF, or UKMET ensemble members predict a track over
 or close to Baja California, it would appear that the small threat
 to Baja California is diminishing.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  22/1500Z 17.3N 107.4W   45 KT  50 MPH
  12H  23/0000Z 18.1N 109.0W   50 KT  60 MPH
  24H  23/1200Z 18.5N 110.5W   60 KT  70 MPH
  36H  24/0000Z 19.0N 112.0W   65 KT  75 MPH
  48H  24/1200Z 19.5N 113.2W   70 KT  80 MPH
  72H  25/1200Z 20.5N 115.0W   70 KT  80 MPH
  96H  26/1200Z 21.3N 116.8W   60 KT  70 MPH
 120H  27/1200Z 22.5N 119.0W   45 KT  50 MPH
 
 $$
 Forecaster Landsea