  Over the last decade there has been mounting evidence that the strength of
the Sun's polar magnetic fields during a solar cycle minimum is the best
predictor of the amplitude of the next solar cycle. Surface flux transport
models can be used to extend these predictions by evolving the Sun's surface
magnetic field to obtain an earlier prediction for the strength of the polar
fields, and thus the amplitude of the next cycle. In 2016, our Advective Flux
Transport (AFT) model was used to do this, producing an early prediction for
Solar Cycle 25. At that time, AFT predicted that Cycle 25 will be similar in
strength to the Cycle 24, with an uncertainty of about 15% . AFT also predicted
that the polar fields in the southern hemisphere would weaken in late 2016 and
into 2017 before recovering. That AFT prediction was based on the magnetic
field configuration at the end of January 2016. We now have 2 more years of
observations. We examine the accuracy of the 2016 AFT prediction and find that
the new observations track well with AFT's predictions for the last two years.
We show that the southern relapse did in fact occur, though the timing was off
by several months. We propose a possible cause for the southern relapse and
discuss the reason for the offset in timing. Finally, we provide an updated AFT
prediction for Solar Cycle 25 which includes solar observations through January
of 2018.
