Tornadoes in the United States Since 2011

#devtools::install_github("rstudio/leaflet")
library("leaflet")
library("dplyr")

## 
## Attaching package: 'dplyr'
## 
## The following object is masked from 'package:stats':
## 
##     filter
## 
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

library("rgdal")

## Loading required package: sp
## rgdal: version: 0.8-16, (SVN revision 498)
## Geospatial Data Abstraction Library extensions to R successfully loaded
## Loaded GDAL runtime: GDAL 1.9.2, released 2012/10/08
## Path to GDAL shared files: /Library/Frameworks/R.framework/Versions/3.1/Resources/library/rgdal/gdal
## Loaded PROJ.4 runtime: Rel. 4.8.0, 6 March 2012, [PJ_VERSION: 480]
## Path to PROJ.4 shared files: /Library/Frameworks/R.framework/Versions/3.1/Resources/library/rgdal/proj

setwd("~/Dropbox/Tornadoes")
Torn = readOGR(dsn = ".", layer = "tornado", 
               stringsAsFactors = FALSE)

## OGR data source with driver: ESRI Shapefile 
## Source: ".", layer: "tornado"
## with 57988 features and 21 fields
## Feature type: wkbLineString with 2 dimensions

Torn$Year = as.integer(Torn$YR)
Torn = subset(Torn, Year > 2010)
ll = "+proj=longlat +ellps=WGS84"
Torn = spTransform(Torn, CRS(ll))

m = leaflet() %>% 
  addTiles() %>%
  addPolylines(data = Torn)
m