Suppose my car won't start. Is there an acceptable explanation which explains how the car fails to start that does not also predict that the car will not start?
For example, I would predict that, if the fuel line were cut, the engine would not start. So, a cut fuel line sounds like an explanation, whether it is probable or not.
However, I cannot accept that my car will not start because "roses are red." Roses are indeed red, and their redness is perfectly consistent with my car not starting. However, the redness of roses does not predict that my car won't start.
Nor would I accept the "explanation" that an undetectable gremlin prevented the engine from starting. The undetectability of gremlins (and their unpredictable nature) renders the gremlin just another word for "ignorance of cause."
So, a plausible explanation is a picture of a cause and effect relationship. If the proposed cause is unknowable, or does not predict the effect, then you don't have an explanation.
Therefore, any valid explanation of a phenomenon must predict that phenomenon from knowable facts (i.e., from chemistry, physics, etc.).
To claim that there is no physical theory that explains a physical phenomenon is to claim that there is no explanation of that phenomenon at all.