893 
 WTPZ42 KNHC 241433
 TCDEP2
 
 TROPICAL STORM FRANK DISCUSSION NUMBER  12
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP072016
 900 AM MDT SUN JUL 24 2016
 
 Frank remains a sheared tropical cyclone with microwave data showing
 the center of circulation located near the northern edge of a large
 mass of deep convection.  The advisory wind speed is kept at 55 kt,
 between the Dvorak estimates that range from 50 to 65 kt.  The main
 controlling factor for Frank's intensity is expected to be gradually
 cooling waters since northeasterly shear is forecast to continue at
 about the same magnitude for the next few days.  Slow weakening is
 forecast by late Monday and beyond due to the cyclone moving over
 marginal waters and eventually into a dry and stable air mass.  The
 new forecast is very close to the previous interpolated official
 prediction, and is a bit lower than the intensity consensus at long
 range.
 
 Microwave data indicate that Frank has turned to the west-
 northwest, now moving at 6 kt.  A ridge centered over the
 southwestern United States seems to be building in over northwestern
 Mexico, causing a mid- to upper-level trough west of the Baja
 California peninsula to move far enough away from Frank to have less
 influence.  Frank should be steered west-northwestward or westward
 at a relatively slow forward speed to the south of that ridge for
 the next several days.  Other than some minor speed differences, the
 guidance continues to be in relatively good agreement, and the
 latest NHC track forecast is basically an update of the previous
 one.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  24/1500Z 20.3N 112.4W   55 KT  65 MPH
  12H  25/0000Z 20.6N 113.3W   55 KT  65 MPH
  24H  25/1200Z 21.0N 114.4W   55 KT  65 MPH
  36H  26/0000Z 21.2N 115.5W   50 KT  60 MPH
  48H  26/1200Z 21.3N 116.8W   45 KT  50 MPH
  72H  27/1200Z 22.2N 119.7W   35 KT  40 MPH
  96H  28/1200Z 23.0N 122.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 120H  29/1200Z 23.0N 125.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
 $$
 Forecaster Blake