  We evaluate the validity of leading models of the Galactic magnetic field for
predicting UHECR deflections from Cen A. The Jansson-Farrar 2012 GMF model
(JF12), which includes striated and random components as well as an
out-of-plane contribution to the regular field not considered in other models,
gives by far the best fit globally to all-sky data including the WMAP7 22 GHz
synchrotron emission maps for Q, U, and I and ~40,000$ extragalactic Rotation
Measures (RMs). Here we test the models specifically in the Cen A region, using
160 well-measured RMs and the Polarized Intensity from WMAP, nearby but outside
the Cen A radio lobes. The JF12 model predictions are in excellent agreement
with the observations, justifying confidence in its predictions for deflections
of UHECRs from Cen A. We find that up to six of the 69 Auger events above 55
EeV are consistent with originating in Cen A and being deflected <18 degrees;
in this case three are protons and three have Z=2-4. Others of the 13 events
within 18 degrees must have another origin. In order for a random extragalactic
magnetic field between Cen A and the Milky Way to appreciably alter these
conclusions, its strength would have to be > ~ 80 nG -- far larger than
normally imagined.
