Solar Storm is supposed to be slamming earth tomorrow. Do we know any affects this could have on our drones?

Unfortunately the effects of a solar storm cannot be fully predicted depending on your location and the intensity of the storm it could affect everything from satelites to power grids.
What effect it would have on flying a drone i have no idea but gps signal loss could be one of the effects you may experience.

In my experience (mavic pilot here) only thing I noticed during a solar event flying has been reduced range and increased interference..  you have fewer GPS to lock into, i was down to 9 from my usually 16-20 I get flying around. But even so the reduced GPS count and reduced connection range didn’t really put a big dent in my flight plans.  

Of course this was a while ago and I’m not sure how bad it was comparatively.. just know my app I used to use for checklists (and since no longer do) alerted me to high Risk solar event occurring..