Headlights blink while driving

[Bdc101]

I have noticed over the past few weeks that I see both my headlights turn off briefly while I am driving. Today I noticed that the fog lights seemed to stay on while the headlights turned off. This happened 3-4 times in the first 5 minutes of my drive this morning, but after that I didn't see it happen again.

Here are some posts that I found on a search that seem similar:
https://xoutpost.com/bmw-sav-forums/...ker-issue.html
https://xoutpost.com/bmw-sav-forums/...lickering.html
I also just ordered a new alternator because my 3-year-old Bosch unit is making a squealing noise... but there have been no lights on the dash or other electrical issues.

Could low voltage or another alternator problem cause the lights to turn off momentarily? What else could cause this sort of problem? Note that my car is a 2003 3.0i with the xenon headlight option.