Nelly would love today’s computer model forecasts for Wednesday. Our “machine” numbers from the GFS and NAM, known as MOS or Model Output Statistics, are forecasting mid 90s tomorrow at Windsor Locks.
MOS is a very useful tool that combines “raw” output from a computer model with regression equations to correlate raw forecasts to observed weather variables. These regression equations use statistics from an individual station to produce a forecast. The GFS is forecasting a raw temperature of 87.3º at 18z tomorrow while GFS MOS is predicting 89º.
Here are the forecasts. The numbers circled in red are the forecast high temperatures for BDL tomorrow.
MOS isn’t always correct and meteorolgists generally are trying to “beat” MOS. It’s not as easy as you might think!