Tornado sightings for the US during 2014 including start and end locations.

library( fields)
## Loading required package: spam
## Loading required package: grid
## Spam version 1.4-0 (2016-08-29) is loaded.
## Type 'help( Spam)' or 'demo( spam)' for a short introduction 
## and overview of this package.
## Help for individual functions is also obtained by adding the
## suffix '.spam' to the function name, e.g. 'help( chol.spam)'.
## 
## Attaching package: 'spam'
## The following objects are masked from 'package:base':
## 
##     backsolve, forwardsolve
## Loading required package: maps
load( "tornado2014.rda")
head( tornado2014)
##   month Fnumber state    lat1     lon1    lat2     lon2
## 1     1       0    GA 34.3328 -84.5286 34.3476 -84.4811
## 2     1       0    VA 37.0250 -76.6377 37.0354 -76.6167
## 3     1       0    VA 36.8769 -76.6721 36.8902 -76.6409
## 4     1       0    VA 37.0800 -76.3000 37.0900 -76.2850
## 5     2       2    IL 39.5180 -90.8410 39.6330 -90.6700
## 6     2       0    IL 39.7853 -90.4215 39.7880 -90.4178

The most popular state …

table( tornado2014$state)
## 
## AL AR AZ CA CO CT DE FL GA IA ID IL IN KS KY LA MA MD ME MI MN MO MS MT NC 
## 55 20  3  9 49  1  1 28 32 56  3 49 28 41 28 15  3  2  4 13 24 47 42  8 32 
## ND NE NH NM NV NY OH OK PA SC SD TN TX VA WA WI WV WY 
## 14 62  2 15  6 11 20 17  9  7 29 18 46 12  3 22  9 13
## sorting the table counts
sort( table( tornado2014$state) )
## 
## CT DE MD NH AZ ID MA WA ME NV SC MT CA PA WV NY VA MI WY ND LA NM OK TN AR 
##  1  1  2  2  3  3  3  3  4  6  7  8  9  9  9 11 12 13 13 14 15 15 17 18 20 
## OH WI MN FL IN KY SD GA NC KS MS TX MO CO IL AL IA NE 
## 20 22 24 28 28 28 29 32 32 41 42 46 47 49 49 55 56 62

Average locations

locX<- (tornado2014$lon1 + tornado2014$lon2)/2
locY<- (tornado2014$lat1 + tornado2014$lat2)/2
plot(locX, locY, col= tornado2014$Fnumber + 1, pch=16  )
map( "state", add=TRUE, col="grey")

load( "USElevation.rda")
image.plot(USElevation, col=topo.colors(256) )
ind<- tornado2014$Fnumber >= 1
points(locX[ind], locY[ind], pch=16, cex=.5 )
map( "world", add=TRUE, col="grey30", lwd=2)