654 
 WTPZ42 KNHC 240836
 TCDEP2
 
 TROPICAL STORM FRANK DISCUSSION NUMBER  11
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP072016
 300 AM MDT SUN JUL 24 2016
 
 Frank's cloud pattern has not changed appreciably in organization
 since the last advisory.  The cloud pattern remains characterized by
 a ball of deep convection with some evidence of outer banding.  An
 0408 UTC Ascat-B overpass suggested winds of around 55 kt, at best.
 The initial intensity estimate is therefore held at this value.
 
 The initial motion estimate is 305/07.  A weak mid- to upper-level
 perturbation near the Baja California peninsula could be responsible
 for Frank's more northwesterly motion today, which is forecast to
 persist for a little longer.  Once this feature dissipates in a day
 or so, Frank should be steered west-northwestward or westward at a
 relatively slow forward speed to the south of a subtropical ridge
 centered over the southwestern United States.  The track guidance is
 in generally good agreement on this scenario, though there are some
 speed differences between the various solutions.  The NHC forecast
 track represents a blend of the ECMWF and GFS solutions and is
 slightly north of the previous forecast after 24 hours.
 
 The cyclone has already moved out of the warmest waters of the
 basin and is forecast to reach sub-26 deg C in about 60 hours.
 This would seem to still give Frank an opportunity to strengthen
 some, but northeasterly to easterly vertical shear over the storm is
 not forecast to abate.  The NHC intensity forecast thus keeps Frank
 at the same strength for a day or so and then shows slow weakening.
 Further weakening should occur by day 3 when Frank reaches
 significantly cooler waters and becomes embedded in a drier and more
 stable air mass.  The guidance suggests that Frank should become a
 remnant low in about 4 days, and so does the official forecast.  The
 new forecast is close to a blend of the statistical-dynamical
 models.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  24/0900Z 19.9N 111.8W   55 KT  65 MPH
  12H  24/1800Z 20.2N 112.7W   55 KT  65 MPH
  24H  25/0600Z 20.7N 113.8W   55 KT  65 MPH
  36H  25/1800Z 21.0N 114.9W   50 KT  60 MPH
  48H  26/0600Z 21.1N 116.2W   45 KT  50 MPH
  72H  27/0600Z 21.9N 119.1W   35 KT  40 MPH
  96H  28/0600Z 22.9N 122.1W   30 KT  35 MPH...POST-TROP/REMNT LOW
 120H  29/0600Z 23.1N 124.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
 $$
 Forecaster Kimberlain