ZCZC HFOTCDCP1 ALL
TTAA00 PHFO DDHHMM
 
Tropical Storm Erick Discussion Number  23
NWS Central Pacific Hurricane Center Honolulu HI   EP062019
500 PM HST Thu Aug 01 2019
 
Southwesterly vertical wind shear of around 30 kt has been taking a
toll on Erick today. Deep convection in the core of the tropical
cyclone has collapsed, revealing an exposed low-level circulation
center. Subjective Dvorak and CIMSS ADT CI numbers remained elevated
at 4.0 to 4.5 due to constraints. However, subjective Dvorak Final T
numbers were down to 3.0 to 4.0, and a partial ASCAT pass measured
weaker than expected winds in the northwest quadrant. Given these
inputs and recent satellite trends, Erick has been downgraded to a
60 kt tropical storm, and the wind radii were reduced.

Erick's exposed low-level center has been decelerating in the past
couple of hours, and after adjustments to earlier positions, the
initial motion is set at 285/11 kt. A continued west-northwestward
motion is expected over the next 48 hours, followed by a turn toward
the northwest and a loss of forward speed as the low- to mid-level
ridge steering Erick is weakened by an upper-level trough. The
forecast track remains to the left of TVCN, favoring the recently
better performing ECMWF and UKMET. It is worth nothing that the 
guidance spread increases beyond 48 hours, though Erick will
have already passed south of the main Hawaiian Islands.

Rapid weakening is expected into tomorrow, followed by continued
slow weakening to remnant low by Monday. During most of the forecast
period, Erick will remain under hostile wind shear produced by an
upper-level trough parked to the northwest. The intensity forecast
reflects a slightly more aggressive weakening trend than the prior
advisory and is in line with ICON, SHIPS, and CTCI. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  02/0300Z 15.9N 154.5W   60 KT  70 MPH
 12H  02/1200Z 16.3N 156.5W   50 KT  60 MPH
 24H  03/0000Z 16.9N 159.0W   40 KT  45 MPH
 36H  03/1200Z 17.7N 161.1W   35 KT  40 MPH
 48H  04/0000Z 18.6N 163.1W   35 KT  40 MPH
 72H  05/0000Z 20.6N 165.8W   30 KT  35 MPH
 96H  06/0000Z 21.9N 167.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  07/0000Z 22.4N 168.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster Wroe
 
NNNN