Friday, May 3, 2013

Script: Use to plot NARR Data

It can be difficult to plot a Skew-T diagram with the online NARR data using the script provided by COLA.  This is because the NARR data files include a bunch of variables that need to be converted before they are compatible with  So I put together a small script using the plotskew function that will perform all of the unit conversions for you.

Additionally, this script prompts you with a real basic GUI function, allowing you to click on a map showing CAPE to get your sounding location.  I usually think this is easier than typing in precise lat/lon coordinates, though if typing in lat/lons manually is your thing, this aspect is easy enough to override.  That's really all there is to it, all other plotting options available in are left unchanged.

List of Conversions:
  • Temperature (From Kelvin to Celcius)
  • Specific Humidity to Relative Humidity
  • Wind Vectors into Meteorological Wind

Oh, and just an FYI, when accessing the NARR dataset online, the large number of calculations made to plot the sounding cause it to take awhile, usually around 5 to 10 minutes.

Download this File


  1. This worked like a charm. I modified a few things, but great easy script. Thanks. I happen to be a grads-addict myself. Just came across it after dabbling in gempak. Grads is much better in my opinion. But what do I know...Im just a mailman who loves weather. Anyway, thanks again.

  2. Glad you liked it! Thank you for the kind words!