Track Hurricane Danny (or any other Unisys-data-available-tropical storm)

track_danny.R

library(leaflet)
library(stringi)
library(htmltools)
library(RColorBrewer)

# get tracks
danny <- readLines("http://weather.unisys.com/hurricane/atlantic/2015/DANNY/track.dat")

# extract data
danny_dat <- read.table(textConnection(gsub("TROPICAL ", "TROPICAL_", danny[3:length(danny)])), 
           header=TRUE, stringsAsFactors=FALSE)

# make storm type names prettier
danny_dat$STAT <- stri_trans_totitle(gsub("_", " ", danny_dat$STAT))

# make column names prettier
colnames(danny_dat) <- c("advisory", "lat", "lon", "time", "wind_speed", "pressure", "status")

# assign colors
danny_dat$color <- as.character(factor(danny_dat$status, 
                          levels=c("Tropical Depression", "Tropical Storm",
                                   "Hurricane-1", "Hurricane-2", "Hurricane-3",
                                   "Hurricane-4", "Hurricane-5"),
                          labels=rev(brewer.pal(7, "YlOrBr"))))

last_advisory <- tail(which(grepl("^[[:digit:]]+$", danny_dat$advisory)), 1)

# draw the map
leaflet() %>% 
  addTiles() %>% 
  addPolylines(data=danny_dat[1:last_advisory,], ~lon, ~lat, color=~color) -> tmp_map

if (last_advisory < nrow(danny_dat)) {
 
   tmp_map <- tmp_map %>% 
     addCircles(data=danny_dat[last_advisory:nrow(danny_dat),], ~lon, ~lat, color=~color, fill=~color, radius=25000,
             popup=~sprintf("<b>Advisory forecast for +%sh (%s)</b><hr noshade size='1'/>
                           Position: %3.2f, %3.2f<br/>
                           Expected strength: <span style='color:%s'><strong>%s</strong></span><br/>
                           Forecast wind: %s (knots)<br/>Forecast pressure: %s",
                           htmlEscape(advisory), htmlEscape(time), htmlEscape(lon),
                           htmlEscape(lat), htmlEscape(color), htmlEscape(status), 
                           htmlEscape(wind_speed), htmlEscape(pressure)))
}

html_print(tmp_map)

@hrbrmstr i try to execute but i habe this error : Error in map$x : $ operator is invalid for atomic vector in line "addPolylines(data=danny_dat[1:last_advisory,], ~lon, ~lat, color=~color) -> tmp_map"

the exact same code ran for me perfectly just now in a clean R session

Some updates for the current season: https://gist.github.com/kmatt/dbf1b67c17ad996d0acb