232 
 WTNT42 KNHC 070838
 TCDAT2
 
 TROPICAL STORM GRACE DISCUSSION NUMBER   8
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072015
 500 AM AST MON SEP 07 2015
 
 Deep convection has redeveloped near the center of Grace overnight,
 and an earlier SSMI microwave overpass showed that the convection
 was organized in a couple of bands around the center.  There are
 indications in geostationary satellite imagery that the shear is
 beginning to increase as the cirrus outflow has become restricted
 over the western portion of the system.  The initial wind speed
 remains 45 kt, which is in agreement with subjective Dvorak
 satellite intensity estimates from TAFB and SAB.  Little change in
 strength is expected today.  Environmental conditions are forecast
 to become less favorable by tonight as westerly vertical wind shear
 increases and dry mid-level air over the tropical Atlantic impinges
 on the circulation.  The shear is forecast to increase to 20-30 kt
 by late Tuesday, and weakening is expected to begin by that time.
 The NHC intensity forecast is close to the LGEM model and the
 intensity consensus.  Given the strong southwesterly upper-level
 winds expected near the eastern Caribbean late in the period, it is
 quite possible that Grace will degenerate to a tropical wave
 before it reaches the Lesser Antilles.
 
 Grace continues to move westward or 275/14 kt.  The tropical
 cyclone is forecast to move generally westward to the south of a
 large mid- to upper-level ridge over the central Atlantic. The
 model guidance is in good agreement on this scenario and the NHC
 forecast is once again essentially an update of the previous NHC
 advisory.  The new track forecast is close to the multi-model
 consensus.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  07/0900Z 13.5N  33.9W   45 KT  50 MPH
  12H  07/1800Z 13.7N  36.1W   45 KT  50 MPH
  24H  08/0600Z 13.9N  39.1W   45 KT  50 MPH
  36H  08/1800Z 14.2N  42.2W   45 KT  50 MPH
  48H  09/0600Z 14.7N  45.4W   40 KT  45 MPH
  72H  10/0600Z 15.5N  51.6W   35 KT  40 MPH
  96H  11/0600Z 16.2N  57.2W   35 KT  40 MPH
 120H  12/0600Z 16.8N  62.5W   30 KT  35 MPH
 
 $$
 Forecaster Brown