  We calculate the general solutions for a warm inflationary scenario with weak
dissipation, reviewing the dissipative dynamics of the two-fluid system, and
calculate the bispectrum of the gravitational field fluctuations generated in
the case where dissipation of the vacuum potential during inflation is the
mechanism for structure formation, but is the sub-dominant effect in the
dynamics of the scalar field during slow-roll. The bispectrum is non-zero
because of the self-interaction of the scalar field. We compare the predictions
with both those of standard, or `supercooled', inflationary models, and warm
inflation models with strong dissipation and consider the detectability of
these levels of non-Gaussianity in the bispectrum of the cosmic microwave
background. We find that the levels of non--Gaussianity for warm and
supercooled inflation are an order of magnitude different.
