Friday, December 16, 2011

New Diagnostic Weather Data Webpage

Friends interested in meteorology:

It is often taught that meteorologists should first diagnose what is currently occurring in their forecast location, why it is occurring, and how it will impact a future forecast. However, it has been my experience (there are likely differing opinions here) that many forecasters today love to skip right to the forecasting step, without taking the time to make a proper diagnosis of what is currently occurring in the atmosphere. They have become so dependent on products (e.g., model QPF) without a proper understanding of how or why the model is generating precipitation. Unfortunately, this model "cancer" has left these forecasters with nothing more than a crutch on which to blame their failed forecast. Don't misunderstand me, computer models are certainly the best tool for forecasting as they can solve fundamental atmospheric equations far more efficiently than any human. However...

What good is any forecast without a proper diagnosis?

Would you purchase a block of shares in a company based solely on a projected stock price? I sure hope not!

Would a good doctor give you medications to treat a disease without some sort of diagnosis?

As you know, there are plenty of graphs and charts on they web that provide diagnostic information for meteorologists (e.g., surface maps, sounding plots, cross section analysis; I have over 10 pages bookmarked!) However, if you are like me, you are often left saying, "What about other fields," or perhaps more commonly, "there has to be a better way to present such data." Personally, I find many plots hard to read, rather cluttered, or just plain visually unappealing. IMO this is partly due to the fact that many people and organizations that present such data care more about ease of production and content rather than the presentation of that data to the user. Surely content is important, but it is ultimately how the user will interpret that data that makes all the difference in the forecast process! Of course, the main challenge here is that personal preference differs amongst forecasters. Some forecasters like a particular color scale, others do not. Some are colorblind. Some cannot interpret a map that is too cluttered. This is similar to one of the main challenges facing graphics design artists!

Last spring I set out on a mission to create appealing maps and provide unique diagnostic fields that I have trouble finding elsewhere on the web. You'll see that many of the maps I provide are nothing more than "pretty colors" to the untrained eye. However, I've tried to make the graphics as visually appealing as possible without sacrificing content (maybe they don't appeal to you; that's fine too!). I'll be the first to admit that the use of a map with a pretty color scale and neat graphics means little if the user fails to interpret it correctly. Unfortunately, this is not a skill you can develop overnight (just ask a veteran forecaster). My favorite reminder of this comes from Bosart (2002):
If you don't like a particular map or would like an alternate color scale, e-mail me and I'll see what I can do. That is one of the [only?] benefits of working on such a product by yourself).

Okay, now for the goodies:

The URL for the new page can be found at

Fields currently offered:

Observational (Based on Sounding or Surface Stations)
  • 300, 500, 700, 850 mb isosurface
  • 0-500m MLCAPE
  • Precipitable Water
  • 12h 500mb Height Change
  • Sounding profiles for selected upper-air stations
  • Surface stations
  • 2m θe
  • Surface moisture flux divergence
  • Cross Sections: KGGW - KLCH ; KLBF - KWAL
  • Isentropic analysis at various θ levels
RUC Initialization Fields (00h Forecast; Interpolated to a 211 AWIPS grid ~80km)
  • 300, 500, 700, 850 mb isosurface
  • 300 mb Divergence
  • 500 mb Absolute Vorticity
  • 500 mb Absolute Vorticity Advection
  • 500 mb Absolute Vorticity and Water Vapor (my personal favorite)
  • 700 mb Absolute Vorticity Advection
  • 700 mb Frontogenesis
  • 500-700 mb Layer Average Q-Vector Divergence
  • 500-850 mb Wind Crossovers
  • 850 mb Temperature & Moisture Advection
  • Trenberth Forcing Term
For more information on the fields, visit the metadata link.

Perhaps my favorite aspect is the ability to select the "ani" versions of these products to easily mouse over previous hours to provide an animation of the trends in the field. This trend analysis is key in a proper diagnosis.

I'm still struggling a bit with exactly how I want to display the hyperlinks to the products. I'm not a big fan of the current frames approach I am using, but the UGA student web-server is currently limited (no access to php). Perhaps this format change in the future when this page migrates to a new web hosting solution.