New updates to the rNOMADS package and big changes in the GFS model

January 16, 2015
By

(This article was first published on Bovine Aerospace » R, and kindly contributed to R-bloggers)

I rolled out a big update to the rNOMADS package in R about two weeks ago.  Now, the list of real time weather, ocean, and sea ice models available through rNOMADS updates automatically by scraping the NOMADS web site.  This way, changes in model inventories will be instantly reflected in rNOMADS without the need for a new version release.

Keep abreast of future updates to rNOMADS by subscribing to the mailing list here.  Feel free to ask for help or make comments on this list as well.

In other news, NOAA just updated the Global Forecast System to provide 0.25 x 0.25 degree output – doubling the resolution of the model!  Check out this crystal clear views of surface temperatures across the planet (source code below the image):

World temperature at 2 m above ground using the 0.25 x 0.25 degree output of the Global Forecast System model.

World temperature at 2 m above ground using the 0.25 x 0.25 degree output of the Global Forecast System model.

 


library(rNOMADS)
library(GEOmap)

#Get dates of model output
model.urls <- GetDODSDates(“gfs_0p25″)

#Find day of most recent model run
latest.model <- tail(model.urls$url, 1)

#Find most recent model run on that day
model.runs <- GetDODSModelRuns(latest.model)

#Get the most recent model (excluding analysis only)
latest.model.run <- tail(model.runs$model.run[which(grepl(“z$”, model.runs$model.run))], 1)

#Define model domain
time <- c(0,0) #Analysis model
lon <- c(0, 1439) #All longitude points
lat <- c(0, 720) #All latitude points
variables <- c(“tmp2m”) #Temperature 2 m above ground

#Get data from NOMADS real time server
tmp.data <- DODSGrab(latest.model, latest.model.run,
variables, time, lon, lat, display.url = FALSE)

#Reformat it
tmp.grid <- ModelGrid(tmp.data, c(0.25, 0.25), “latlon”)

#Define color scale
colormap <- rev(rainbow(500, start = 0 , end = 5/6))

#Plot it
image(x = tmp.grid$x, y = sort(tmp.grid$y), z = tmp.grid$z[1,1,,], col = colormap,
xlab = “Longitude”, ylab = “Latitude”,
main = paste(“World Temperature at Ground Level:”,
tmp.grid$fcst.date))

plotGEOmap(coastmap, border = “black”, add = TRUE,
MAPcol = NA)

To leave a comment for the author, please follow the link and comment on their blog: Bovine Aerospace » R.

R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: Data science, Big Data, R jobs, visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...



If you got this far, why not subscribe for updates from the site? Choose your flavor: e-mail, twitter, RSS, or facebook...

Comments are closed.

Sponsors

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)