479 
 WTPZ45 KNHC 011446
 TCDEP5
 
 Tropical Storm Hector Discussion Number   4
 NWS National Hurricane Center Miami FL       EP102018
 800 AM PDT Wed Aug 01 2018
 
 Satellite images indicate that Hector is on a strengthening trend,
 with a large area of convection near and west of the apparent
 center. The latest microwave data, a 1159Z F-16 pass, also show the
 beginnings of an inner core in the 91-Ghz channels. The system has
 some tilt, however, with suggestions from the microwave pass that
 the low- and mid-level centers are not well aligned.  The latest
 intensity estimates from TAFB/SAB are 45 kt, but I've elected to
 only raise the wind speed to 40 kt due to uncertainty in the initial
 position and the microwave tilt.
 
 Hector is forecast to remain over warm water, with light-to-
 moderate shear and somewhat dry mid-level moisture for the
 next several days.  In 12 to 24 hours, northeasterly shear is
 forecast to increase near Hector, which should slow the
 intensification rate.  Thus the official forecast shows
 strengthening at less than a climatological rate for the next
 few days.  At long range, some of model guidance suggest the
 upper-level environment could become very favorable, with the
 HWRF/HMON now showing Hector at category 4 strength in the central
 Pacific Ocean.  I would prefer to see more consistency from these
 models before showing such a large increase, but the new forecast is
 raised from the previous one and is higher than the model consensus.
 
 The storm is moving west-northwestward at 11 kt.  Hector should
 turn to the west tomorrow and even move a little south-of-west for
 the next few days thereafter as the subtropical ridge builds to the
 north and west of the cyclone.  The largest uncertainty is the
 location of Hector in a few days as an inverted upper-level trough
 forms to the north or northeast of the cyclone.  For now there is
 enough separation of Hector and this trough to prevent the cyclone
 from gaining much latitude.   While the model guidance doesn't show
 a lot of spread for now, and the new forecast is close to the
 previous one, it is worth keeping an eye on the trough to make sure
 it stays separate from Hector at long range.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  01/1500Z 13.8N 120.4W   40 KT  45 MPH
  12H  02/0000Z 14.2N 122.0W   50 KT  60 MPH
  24H  02/1200Z 14.5N 124.1W   55 KT  65 MPH
  36H  03/0000Z 14.6N 126.4W   60 KT  70 MPH
  48H  03/1200Z 14.5N 128.7W   65 KT  75 MPH
  72H  04/1200Z 14.4N 133.5W   75 KT  85 MPH
  96H  05/1200Z 13.9N 138.2W   90 KT 105 MPH
 120H  06/1200Z 13.7N 142.0W   90 KT 105 MPH
 
 $$
 Forecaster Blake