765 
 WTPZ44 KNHC 142034
 TCDEP4
 
 Tropical Depression Four-E Discussion Number   1
 NWS National Hurricane Center Miami FL       EP042018
 400 PM CDT Thu Jun 14 2018
 
 Overnight scatterometer data indicate that the circulation of the
 system was open on the northwestern side.  High-resolution GOES-16
 1-min visible data indicate that the low is now closed, with a
 well-enough defined circulation center.  Since there is plenty of
 banded convection, this system is being designated as a tropical
 depression, and the initial wind speed of 30 kt is based off the
 overnight scatterometer data.
 
 The initial motion estimate is an uncertain 325/5 kt.  A weak
 mid-level ridge over Mexico is forecast to break down by tomorrow,
 leaving the depression in an area of light steering currents.  Much
 of the model guidance linger the system just south of the coast of
 Mexico for the next couple of days until the cyclone gets drawn
 northward into a larger trough currently seen over the western Gulf
 of Mexico.  There is considerable uncertainty in the timing of this
 poleward motion, however, with the UKMET, HMON, and COAMPS-TC models
 faster than the rest of the guidance.  This seems like a pretty
 clear case of staying near the model consensus, given the weak
 steering flow that makes it nearly impossible to choose one model
 over another one.  Thus, the official forecast shows a slow
 northward motion, near the eastern Pacific model consensus TVCE, and
 it should be emphasized that the forecast timing of landfall is
 subject to large changes in the future.
 
 The system is not particularly well organized at the moment, with a
 few swirls seen in the visible imagery rotating around the larger
 gyre.  After the low consolidates, light-to-moderate shear with
 very warm waters, and high mid-level humidity should lead to steady
 intensification.  This is a tricky forecast, however, since land is
 so close to the north, which would prevent much strengthening.  The
 official forecast is a blend of the statistical-dynamical guidance
 and the regional hurricane guidance, a bit lower than the model
 consensus since the HWRF keeps the cyclone well offshore (unlike
 the official prediction), leading to a stronger storm.
 
 It has been an active early part of the eastern Pacific season.
 This is the 2nd earliest 4th tropical cyclone on record in the
 basin during the satellite era (1966-present), only 6 hours behind
 the previous record in 1974.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  14/2100Z 15.5N 100.1W   30 KT  35 MPH
  12H  15/0600Z 16.1N 100.5W   30 KT  35 MPH
  24H  15/1800Z 16.3N 100.6W   35 KT  40 MPH
  36H  16/0600Z 16.5N 100.5W   40 KT  45 MPH
  48H  16/1800Z 16.7N 100.3W   50 KT  60 MPH
  72H  17/1800Z 17.1N 100.3W   40 KT  45 MPH...INLAND
  96H  18/1800Z 17.5N 100.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 120H  19/1800Z...DISSIPATED
 
 $$
 Forecaster Blake