When “1000-Year” storms happen frequently, they are no longer anomalies. This is #ClimateChange.
All 8 Billion people will not die out.
People often use "End of civilization" and "end of humanity" interchangeable, but no, I don't think the world will become so inhospitable that a population too small to breed will be all that is left.
Just like the twinkie and the cockroach, human beings will survive the apocalypse. Maybe even with rather high tech intact. But it will not be in central US for example since that will once again be a sea, like it used to be.