> also weather does not usually confine itself to state boundaries. This is a very good point. During the height of the 2011 Super Outbreak [0], April 27th, ma

> also weather does not usually confine itself to state boundaries. This is a very good point. During the height of the 2011 Super Outbreak [0], April 27th, many of the strongest tornadoes crossed state lines. Taken as a whole, the event lasted four days and spawned tornadoes as far north as New York, south to Florida, east to Arkansas and west to the Carolinas. Here's the thing: thanks to NWS forecasting and climate modeling, we had DAYS of warning that this was probably going to be a very bad storm. Obviously, they can't tell you X tornado is going to hit Y neighborhood, but from a standpoint of getting pre-warning out, we had lots of notice that things were going to be tough. Historically, the deadliest tornado in American history was the Tri-State tornado [1], that started in Missouri and ended in Indiana. None of these could be taken individually as they were all part of the same large mesoscale system. Lots of ingredients go into a good climate model, from which good predictions can be made. On an "average" severe weather event, from where I live (Huntsville, northern part of Alabama just south of the Tennessee border), storms usually fire up across central Mississippi, move rapidly northeast across Alabama and dissipate or weaken as they move into eastern Tennessee. [0] https://en.wikipedia.org/wiki/2011_Super_Outbreak https://en.wikipedia.org/wiki/2011_Super_Outbreak [1] https://en.wikipedia.org/wiki/Tri-State_Tornado https://en.wikipedia.org/wiki/Tri-State_Tornado