029 
 WTPZ41 KNHC 282036
 TCDEP1
 
 TROPICAL STORM ANDRES DISCUSSION NUMBER   3
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP012015
 300 PM MDT THU MAY 28 2015
 
 The satellite presentation of Andres continues to improve, with a
 band of convection now wrapping about three-quarters of the way
 around the center.  A recent ASCAT pass revealed maximum winds
 of about 50 kt, so the initial intensity has been increased
 accordingly.  The scatterometer data also provided a better
 estimate of the size of the tropical cyclone wind field, and the
 tropical-storm-force wind radii have been adjusted outward.
 
 The satellite data indicate that the center is located a bit
 southwest of the previous estimate, but the overall initial motion
 remains west-northwest or 295 degrees at 10 kt.  The track forecast
 reasoning is unchanged from before.  Andres should move west-
 northwestward to northwestward around the southwestern portion of a
 mid-level ridge extending westward over the eastern Pacific from
 central Mexico.  The 1200 UTC global models show more ridging to the
 north of Andres late in the period than previous runs, which has
 resulted in a westward shift in the track guidance.  The NHC
 forecast has been adjusted westward, but it lies along the right
 side of the guidance envelope.
 
 Environmental conditions consisting of warm water and low shear
 should allow for continued steady strengthening during the next
 couple of days.  Although the latest SHIPS RI index shows a lower
 chance of rapid strengthening during the next 24 hours than this
 morning, it would not be surprising if rapid intensification
 occurred.  The NHC forecast is near the upper end of the intensity
 guidance and is closest to the SHIPS model.  After 72 hours, Andres
 should begin to weaken when it encounters slightly cooler sea
 surface temperatures and a drier and more stable airmass.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  28/2100Z 11.6N 112.5W   50 KT  60 MPH
  12H  29/0600Z 12.3N 113.6W   65 KT  75 MPH
  24H  29/1800Z 13.1N 114.7W   75 KT  85 MPH
  36H  30/0600Z 13.9N 115.3W   85 KT 100 MPH
  48H  30/1800Z 14.9N 116.0W   90 KT 105 MPH
  72H  31/1800Z 16.5N 117.7W   85 KT 100 MPH
  96H  01/1800Z 17.5N 120.0W   70 KT  80 MPH
 120H  02/1800Z 18.0N 122.5W   55 KT  65 MPH
 
 $$
 Forecaster Brown