Sudden/Rapid onset migraines

SO - I've had migraines my entire life, starting when I was an infant even (I had crying jags for days that they couldn't explain) and they were mostly about 2-3 a year until I hit my teens where they ramped up to 1/month. By the time I was 17-18 I started having several a week & for the last 13 years they've become daily, with a baseline of pain that never stops at any time (usually around 4-6/10 on the pain scale).

I used to have a warning period for all of my episodes for about 30 mins where I'd start feeling 'off' for lack of a better word & then the pain would gradually grow up to whatever extreme it decided to reach by the time it was at its worst - usually over the course of an hour. For the last couple years, however, all of that has become drastically sped up - they go from 0-60 in about 20 minutes, and about ever 2 out of 10 times they'd come on like a thunderclap headache where it feels like someone suddenly hits me in the head with a sledgehammer & I'm immediately at the worst part of my episode.
I've mentioned it to both of my neurologists (the one who I used to see & the new one) but they don't know why they would behave this way.
Does this happen for anyone else?
Is there some version of thunderclap headaches for migraines where they come on suddenly & then stick around once they hit?