What might cause an evening of vertigo symptoms. all is well this morning.?

Several issues: The vertigo could be due to a medication, alcohol, recreational drugs, or inner ear problems, such as otolithic shifting, when certain positional changes occur (positional or postural vertigo). Occasional migraine patients experience "paroxysmal vertigo", and rarely, pts with epilepsy will experience transient dizziness as an aura. See your doc if this recurs.