Differences between forecasting models such as GFS, NAM, etc.

[the_photon]

Hey all,

My question: There are several major forecasting models out there, such as GFS, NAM, RUC, etc. I am hoping that someone can point me to a web page that explains all the differences between these.

As I understand it, some of these models take in to account geographic features like mountains while others assume a level surface everywhere -- some of these models are more accurate about some things (like high/low temps) in certain places and so forth. However, I am looking for more detailed and specific information than this. I am also looking for fine grained details about differences between GFS-MAV vs. GFS-MEX, etc. I know that GFS is the global forecasting system (the free one) and NAM is north american mesoscale, but the MAV vs. MEX is alphabet soup to me.

Seeing as how I have just asked such a large question, I would be perfectly fine if someone could post some links to pages that explain these things.

Thanks,
the_photon

 

[Jeff Duda]

Hey all,

My question: There are several major forecasting models out there, such as GFS, NAM, RUC, etc. I am hoping that someone can point me to a web page that explains all the differences between these.

This is a good place to start for the American models: http://www.emc.ncep.noaa.gov/
For models run by other countries, you'll have to poke around on their specific web sites. For the Canadian models: http://weather.gc.ca/charts/index_e.html. For the ECMWF: http://www.ecmwf.int/

As I understand it, some of these models take in to account geographic features like mountains while others assume a level surface everywhere -- some of these models are more accurate about some things (like high/low temps) in certain places and so forth.

All real-data models incorporate topography. The only difference is how well resolved some smaller topographical regions are (like individual peaks in the Rockies) and what vertical coordinate the models use (i.e., isobaric, isentropic, terrain-following, hybrid etc.)

I am also looking for fine grained details about differences between GFS-MAV vs. GFS-MEX, etc. I know that GFS is the global forecasting system (the free one) and NAM is north american mesoscale, but the MAV vs. MEX is alphabet soup to me.

Those are specifically MOS products. The only difference is that one of them (GFS-MEX) is an EXtended version of the 60 hour GFS/AVN MOS output. The model they are derived from is the same.