MWU's Weather Guru, Chris Bedford reflects on Weather Models
Back in “the day” when I was first studying meteorology at The University of Michigan (between sandwiches from Zingerman’s Deli), it was still early days in the application of weather models. Global models were only just becoming practical, with the Global Spectral Model entering service in 1982. The model had a horizontal resolution roughly 2.5 degrees and just 12 vertical layers, with both the horizontal and vertical resolution decreasing at longer forecasts. For regional forecasts, the Limited Fine Mesh model was available over North America at a resolution of around 125 km - so coarse it didn’t even resolve the Great Lakes!
With steady improvement in computer and communication speeds over the years, model resolution, performance, and availability has improved steadily and dramatically. Today, I can count at least 12 reasonably good Global Models running in operational mode – some under 10 km horizontal resolution and often well over 100 vertical layers. While resolution and run frequency varies among the models, all bring something to the table when it comes to forecast guidance – especially over open ocean. In addition, multiple global models are run in an ensemble manner (reference Marine Weather University Advanced Course), providing hundreds of additional global model runs per day!
At the continental, regional, and local scales, the number of available models is even more staggering, with many models run for specific areas around the world by national meteorological agencies, universities, and private entities. These higher resolution models are extremely useful for providing guidance in forecasting near-coastal winds.