  Evidence strongly indicates that the strength of the Sun's polar fields near
the time of a sunspot cycle minimum determines the strength of the following
solar activity cycle. We use our Advective Flux Transport (AFT) code, with
flows well constrained by observations, to simulate the evolution of the Sun's
polar magnetic fields from early 2016 to the end of 2019 --- near the expected
time of Cycle 24/25 minimum. We run a series of simulations in which the
uncertain conditions (convective motion details, active region tilt, and
meridional flow profile) are varied within expected ranges. We find that the
average strength of the polar fields near the end of Cycle 24 will be similar
to that measured near the end of Cycle 23, indicating that Cycle 25 will be
similar in strength to the current cycle. In all cases the polar fields are
asymmetric with fields in the south stronger than those in the north. This
asymmetry would be more pronounced if not for the predicted weakening of the
southern polar fields in late 2016 and through 2017. After just four years of
simulation the variability across our ensemble indicates an accumulated
uncertainty of about 15\%. This accumulated uncertainty arises from stochastic
variations in the convective motion details, the active region tilt, and
changes in the meridional flow profile. These variations limit the ultimate
predictability of the solar cycle.
