178 
 WTPZ45 KNHC 262032
 TCDEP5
 
 Hurricane Rosa Discussion Number   7
 NWS National Hurricane Center Miami FL       EP202018
 300 PM MDT Wed Sep 26 2018
 
 Rosa continues to strengthen this afternoon. Improved deep
 convective banding features with -83C cloud tops are evident in both
 visible and microwave images, particularly in the east semicircle.
 The initial intensity is bumped up to 70 kt and is a compromise of
 the subjective and objective satellite intensity estimates.
 
 It still appears likely that Rosa will continue to quickly
 strengthen through this evening while it moves over warm oceanic
 temperatures and in a high moisture and low shear atmospheric
 environment.  The official forecast is based on a blend of the IVCN
 and NOAA-HCCA intensity consensus models, and shows strengthening,
 at a slower pace, after the RI period.  Beyond 48 hours, steady
 weakening is forecast due to decreasing sea surface temperatures,
 increasing southwesterly shear, and a high statically stable
 surrounding environment.
 
 Rosa is currently moving west-northwestward, or 285/9 kt, within the
 mid-level easterly steering flow produced by a mid-level ridge
 extending from northern Mexico westward over the eastern Pacific.
 At around day 3, Rosa is expect to move northwestward and then
 northward day 4 in response to a mid-latitude trough approaching
 from the northwest.  The along track spread beyond day 3 continues
 to be an issue with the GFS global and HWRF hurricane model
 indicating a much more faster north to north-northeast motion
 than the slower European model cluster.  In this scenario,
 the NHC forecast will remain near the better performing various
 multi-model consensus models.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  26/2100Z 16.5N 112.2W   70 KT  80 MPH
  12H  27/0600Z 16.7N 113.6W   90 KT 105 MPH
  24H  27/1800Z 16.9N 115.3W  100 KT 115 MPH
  36H  28/0600Z 17.2N 116.7W  105 KT 120 MPH
  48H  28/1800Z 17.8N 117.7W  110 KT 125 MPH
  72H  29/1800Z 20.1N 119.4W   95 KT 110 MPH
  96H  30/1800Z 23.3N 119.2W   80 KT  90 MPH
 120H  01/1800Z 26.6N 117.5W   60 KT  70 MPH
 
 $$
 Forecaster Roberts
 
 

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