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

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.



#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) <- tail(model.runs$[which(grepl(“z$”, model.runs$], 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 <- DODSGrab(latest.model,,
variables, time, lon, lat, display.url = FALSE)

#Reformat it
tmp.grid <- ModelGrid(, c(0.25, 0.25))

#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:”,

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

Fall 2014 Solar Balloon Flights

We had a record number of successful solar balloon launches this fall:  a total of three!  Two of these balloons carried messages in bottles (in case they landed in water) and one just carried a handwritten note.  Unfortunately, no one has come across our messages as of now.  I suspect this means the bottles came down on land somewhere.  Probably some hunter will come across one two decades from now.

We’ve been using paint pigment to darken the balloons – it’s pretty labor intensive because you have to rub the powder into the plastic.  As a result, these balloons were not dark enough and so had pretty bad lift.  Our newest bag (currently under my desk in my graduate student office) is quite a bit darker, and I might give it a once over before I try and send it off.  It’ll be carrying a tracker and a camera, so we’re waiting on light winds before flying.

1.  The 7′ tetroon

Master solar balloon builder Mathew Lippincott sent me a 7′ tetroon to test out earlier last year.  I was pretty excited because I’ve never tried flying a tetroon.  We got it a little dark (but should have spent more time on it), and managed to get it to lift one bottle with a message inside.  Here it is orbiting a parking lot, bouncing off a tree, inching over a busy street at about 30′ elevation, and finally heading skyward:

Thankfully my friend didn’t film the street crossing, because I thought there was going to be a solar balloon/car collision for sure.  Students walking by were pointing and asking if it was a weather balloon.  Hardly!

2.  The 22′ tetroon fail

Not-so-master solar balloon builder glossarch (yours truly) tried to make a tetroon back in 2013.  I made a mistake somewhere down the line and it ended up looking like a giant pillowcase.  Nevertheless, I figured I could get it to fly…and I was right. A bystander thought it was a hang glider.  Come on!  A flying pillowcase holding a Trader Joe’s bag full of bottles resembles no hang glider I’ve ever seen.  To each their own, I guess…

The pillowcase being inflated using vacuum cleaner exhaust.

The pillowcase being inflated using vacuum cleaner exhaust.

3.  Halloween Solar Balloon!

What could be better than a paint dropcloth ghost hovering ominously over your town on Halloween?  I sealed the bag in record time (about 20 minutes) simply by unrolling a swath of paint dropcloth and ironing each edge together to make a cylinder.  Then we drew a scary ghost face on it, scrubbed some pigment on the plastic, and waited for Halloween.  Initially, we had a styrofoam tombstone as payload.  But the tombstone was too heavy, so we ended up just attaching a note and launching.  Because the bottom of the balloon was so poorly ballasted, the whole thing cavorted around in midair quite a bit, even turning sideways a couple of times.  Due to calm winds near the surface we had quite a few witnesses.

Inflating the beast.

Inflating the beast.

Haunting Chapel Hill on Halloween 2014.

Haunting Chapel Hill on Halloween 2014.

A big thanks to Xiao Yang for taking photos and video!  See his Flickr albums here.