severe weather

we keep getting severe weather around the greater williamsburg area. pockets of nothing that turn into violent thunder storms and high winds. tree branches break, gutters are flooded, people carrying umbrellas do their best mary poppins impressions. it's like weather but, you know, more severe. it makes me wonder how other things might modify if "severe" were attached.
it also makes me wonder about the difference between severe and severity as they relate to weather. i don't think i've ever heard a meterologist talk about "the weather's extreme severity" and i don't know what that would really mean.