  The solar modulation effect of cosmic rays in the heliosphere is an energy-,
time-, and particle-dependent phenomenon which arises from a combination of
basic particle transport processes such as diffusion, convection, adiabatic
cooling, and drift motion. Making use of a large collection of time-resolved
cosmic-ray data from recent space missions, we construct a simple predictive
model of solar modulation which depends on direct solar-physics inputs: the
number of solar sunspots and the tilt angle of the heliospheric current sheet.
Under this framework, we present calculations of cosmic-ray proton spectra,
positron/electron and antiproton/proton ratios and their time dependence in
connection with the evolving solar activity. We report evidence for a time-lag
$\Delta{T}=8.1\pm\,1.2$ months, between solar activity data and cosmic-ray flux
measurements in space, which reflects the dynamics of the formation of the
modulation region. This result enables us to forecast the cosmic-ray flux near
Earth well in advance by monitoring solar activity
