About GrADS-aholic!

Hello!  I am starting this blog because throughout my undergraduate and graduate career in meteorology and atmospheric science, I have developed a hearty knowledge of the free Grid Analysis Display System (or GrADS) software package.  Most of my skills come from trial and error, as well as what I like to call "precision Googling."  After acquiring the lot of my skills, I feel as if I have something to contribute in this area.  In a nutshell, this blog is basically my attempt to provide everyone with a lot of tools and tips that I wish I had while I was learning/using GrADS.  I welcome feedback and questions related to this blog, and GrADS in general.

Update (2017): If you frequent the site you have probably noticed that I have not added any new scripts or tutorials in over a year.  Unfortunately, I have not had enough time to sit down and thoroughly construct and test any new features and functions... And honestly, I've been doing most of my recent work in python.  That said, I do still have several scripts and tutorials that I want to publish on this blog this upcoming year.... so stay tuned as they say. 

Lets start with the basics, below is a list of advantages and disadvantages to using the software.

Advantages

• Free/Easy to install
• Works well on Windows
•  Easy to learn scripting/good introduction into computer programming
• Quick and easy access to real time and reanalysis weather data through interface
•  Compatible with shapefiles
• Possible to develop GUI interface using scripting Language
• KML/PNG/JPG/GIF/TXT/DAT file output
• Large library of scripts available online
• Does not use a ton of memory
• Models such as WRF and the Bryan Cloud Model (CM1) include GrADS output options

Disadvantages

• Not as powerful as other plotting software (e.g., Python, NCL)
• In my opinion, GrADS produces relatively low quality images (compared to Matlab,Python, etc)
• Can only handle gridded and station data files (Grib/NETCDF) with appropriate control file
• Cannot perform high level data functions such as EOF analysis
• Cannot easily plot "Generic vertical cross sections" (that is anything other than East/West or North/South)

It is because of the disadvantages that GrADS seems to becoming less and less preferred to other plotting languages, but it is still a very useful tool.  If you are still wondering if GrADS is right for you, I included a few example images made with GrADS to give you an idea of what GrADS can be used for.

Visible Satellite Data and Counties

Surface weather map from the NAM model

NARR Reanalysis Precipitable Water

So, now that you have an idea of what to expect with GrADS, I will provide a few links and some basic info so you can get started.  Now, I presume if you are here you probably have GrADS installed on your computer and you probably are just looking for a few scripts to help you make some bad-ass weather plots.  I mean, I highly doubt you just stumbled across this in your spare time and decided to get started with GrADS based on the information in this post, but just in case you did here is a paragraph describing how to install the software.

So the first thing you will want to do is get the GrADS software installed on your computer.  As I recall, installing the software was as easy as going to This Website and downloading the version you want, untarring/unzipping the folder and installing it.  Note, if you are using windows you will need Cygwin installed, however, I believe it comes as part of the GrADS package available for windows, so this should be fairly straight forward.  The installation comes with a bunch of different executable files (all listed on the website), I have personally never used anything other than the basic "grads" executable.

In windows you can open the GrADS interface by double-clicking the executable file (linux just typing "grads" into your console should do the trick).  GrADS first opens a command shell and prompts you to choose "landscape" or "portrait" for your image dimensions (the default is landscape).  Once you make your choice, a second window will open up.  This window will be where your data is plotted.  So basically, you have a command console to enter commands, and a display console where your data will be plotted.  Once you have these windows up, all that's left is to learn the commands!

Now instead on going through a detailed instruction on how to use commands in GrADS, I am going to go ahead and point anyone new to GrADS to This Tutorial to help get you started.  This is just because I don't want to repeat a ton of information, and I feel like going through the basics might be a little redundant.  Anyway, once you have gone through the tutorial and have a basic idea of the different functions you can use with GrADS, I encourage you to come back here and browse the different scripts/tutorials I have on this blog.

All ad revenue generated from this site (while comically minuscule) will be donated to the Association for Women in Science and National Public Radio.

So I think that's it for the introduction, I hope you found this page useful, check back often for newly added scripts, and tutorials!