  We describe a new microlensing-event alert algorithm that is tailored to the
Korea Microlensing Telescope Network (KMTNet) multi-observatory system. The
algorithm focuses on detecting "rising" events, i.e., events whose brightness
is increasing as a function of time. The algorithm proceeds in three steps. It
first identifies light curves with at least $N_{\rm high}$ points that are at
least $3\sigma$ above the median and that had been taken since shortly before
the previous search for new events. It then demands that there are at least
$N_{\rm high}$ $\textit{consecutive}$ high points when considering any
combination of light curves from one, two, or three observatories. Finally, it
fits to a "rising microlensing model" consisting of a broken line, i.e., flat
before some time $t_{\rm rise}$ and rising linearly afterward. If this fit is
better than a flat line by $\Delta\chi^2>\Delta\chi^2_{\rm thresh}$, the light
curve is sent for human review. Here, $(N_{\rm high},\Delta\chi^2_{\rm
thresh})=(5,250)$ or $(10,400)$, depending on the field cadence. For 2018,
KMTNet alerts will initially be restricted to a few northern bulge fields and
may gradually extend to the full northern bulge. Further expansion of coverage
is expected in 2019.
