To recreate interactive symbols, examine your data and determine the number of categories (classes) to represent.
This map takes on a massive, complicated dataset— three decades of tornadoes in the US. We see different patterns each year for the number of tornadoes, where they strike, and the direction they travel. We love this map because it tells many compelling stories. We see, for example, overall fatalities have declined through the years, but then we look at 2011 and see we still have a lot to learn.
This map is exceptionally interactive and rewards you with every click. You really see the power and patterns of these storms as you zoom in to explore a region, click on symbols for details about a particular tornado, and select from the table to see incidents by year. You can also get a different perspective when you view by city, by state, or the entire US.
I grew up in the Midwest, loving maps and having occasional bad dreams about twisters. Current passions: story maps, birds, family.
If you liked this map, check out these other Maps We Love that explore similar topics.