Jeff Snyder and Rob Dale have it right ... but I'd add that GREarth doesn't really have a target audience. It's more of a program I wrote to help me, a non-meteorologist, understand why the weather is behaving the way it is -- i.e. the big picture. One incident brought this home to me and was one of the main motivators for GREarth: several years ago I was watching a nice storm in western OK in GR2Analyst and posted on the grlevelx.com forums that it looked like a tornado would form. Rdale replied that nothing would happen because the storm was "elevated". Sure enough, nothing happened. It was obvious that no matter how sophisticated your radar app was (xsections, volumetric radar, etc., etc.), it couldn't give the entire picture.
A second motivation for the RUC severe weather fields was Greg Stumpf's presentations on PHI. I wanted to see if the RUC could indicate where there was the potential for severe storms and tornadoes in the short term (+3hrs). This led to combining RUC forecast reflectivity with forecast SCP and STP. The result is somewhat of an automated, graphical MCD. I'm pretty happy with the results even though it overforecasts the extent of the threat.
For hurricane watching, the satellite imagery was a must. GREarth covers all the critical sectors with VIS, IR, and WV. Given the spatial extent of the sat coverage, a spherical Earth projection was needed, hence the "Earth" part of the program.
Also, I wanted a program that would help with monitoring Winter weather down South. We're always in marginal conditions here. That led to the inclusion of precip-typed radar, LSRs, and METAR current conditions. The precip typing is derived from the RUC using the Canadian Energy algorithm and is combined with the actual reflectivity in a novel way at render time. A method that gives users an idea of the uncertainty in the typing.
It's important to note that GRS isn't really a "business" in the usual sense. It's one guy writing software. I don't do market research, target specific segments, etc. And, as with all the GRS programs, it'll be the users that mostly define where GREarth goes from here.
Mike
PS. I noticed recently that GREarth does not, in fact, have a mesoanalysis field that indicates whether storms are in an elevated environment! I'm working to remedy that situation now but it probably won't make it into 1.00. There's apparently no official definition/algorithm used to determine whether a sounding shows "elevated" conditions or not. After discussions with some mets, I now have a algorithm that should work as a first cut.
