429 
 WTPZ44 KNHC 300839
 TCDEP4
 
 TROPICAL STORM GUILLERMO DISCUSSION NUMBER   2
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092015
 200 AM PDT THU JUL 30 2015
 
 GOES satellite imagery show that the cloud pattern has become better
 organized with numerous cyclonically curved convective bands around
 the center of circulation. The upper-level outflow has improved
 during the past several hours. Dvorak T-numbers are now 3.0 and
 2.5 from TAFB and SAB, respectively. Thus, the depression has been
 upgraded to Tropical Storm Guillermo with an initial intensity of
 35 kt. Guillermo is the seventh tropical storm of the 2015 eastern
 north Pacific hurricane season.
 
 The environment of low shear and warm SSTs is quite favorable for
 strengthening, and Guillermo will likely become a hurricane in about
 36 hours. The probability of rapid intensification included in the
 SHIPS guidance is 32 percent. After 72 hours, both cooler ocean and
 increasing shear will likely induce gradual weakening. The NHC
 forecast follows very closely the intensity consensus.
 
 The best estimate of the initial motion is toward the west-
 northwest or 285 degrees at 13 kt. Guillermo is well embedded within
 the deep easterly flow south of a moderate subtropical ridge. There
 is high confidence that this pattern should keep the cyclone on this
 general track for the next 2 to 3 days, given that the guidance is
 tightly clustered during that period. After that time, Guillermo
 will reach the western edge of the ridge and will turn more to the
 northwest toward a mid-latitude trough. The NHC track forecast is
 similar to the previous one and is basically on top of the consensus
 of the ECMWF and the GFS global models.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  30/0900Z  8.5N 126.3W   35 KT  40 MPH
  12H  30/1800Z  8.9N 128.2W   45 KT  50 MPH
  24H  31/0600Z 10.1N 131.1W   55 KT  65 MPH
  36H  31/1800Z 11.2N 134.2W   65 KT  75 MPH
  48H  01/0600Z 12.2N 137.4W   75 KT  85 MPH
  72H  02/0600Z 14.5N 141.6W   70 KT  80 MPH
  96H  03/0600Z 16.3N 144.3W   65 KT  75 MPH
 120H  04/0600Z 18.0N 146.5W   55 KT  65 MPH
 
 $$
 Forecaster Avila