WSET.com - ABC13Why the Differences? by Sean Sublette

We are often asked, "Why is your forecast different from The Weather Channel?"

First, it is important to understand that our mission is different than that of The Weather Channel (TWC).  They are most interested in showcasing the big national weather stories.  We are interested in Virginia.

True, our meteorology staff looks at much of the same data that the meteorologists do at TWC.  However, TWC uses a tremendous amount of automation in the forecasting process.  They have to.  They do not have the resources to put together a customized (read: human) forecast for every single county and town in the United States.

Their process is similar to what many large private forecasting firms use.  A national forecast database is generated from a computer.  The database is initialized with data from a suite of numerical simulations.  Some of those simulations are proprietary, some are public domain.

From there, a group of meteorologists will check the entire database for potential errors.  From what I can tell from TWC's web site, their database covers the entire country for 10 days.  While I have not recently spoken directly to anyone at TWC about the database, a friend of mine who used to work there suggested that a group of 3-6 meteorologists checked the entire database for accuracy.

So that's 3-6 meteorologists covering the whole country… 10 days into the forecast period.  I have a hard time imagining one of them assigned to just Lynchburg, Danville, or Roanoke.

Plus, TWC is in Atlanta.  Yes, a meteorologist can make a forecast for anywhere… from anywhere.  But we have the advantage of actually living in our forecast area and seeing the weather firsthand.  We have learned the area's weather quirks.

So, in situations where the forecast and observation data do not obviously point to a particular forecast idea, there will be discrepancies.  Sometimes, they will be large.  And, to be fair, we will get beaten by TWC on occasion.  But we believe that in the long run, we will be more reliable and more accurate than the folks in Atlanta.