I think the data speak for themselves...
http://www.emc.ncep.noaa.gov/gmb/STATS/html/new_aczhist.html
Yes, they change, as the data input based on obsevrations etc. change, and this will always be the case with NWP output (surely)? And no the models do not always get it spot on, especially a few days out but there is little doubt they are much better than they were ten plus years ago. (Ten years of improvements are not negated by a few different output options for one weekend 😉 )
Originally Posted by: doctormog