Enlarge / 12z European operational model landfall location for Hurricane Irma. (credit: Ryan Maue/Twitter)
If you closely follow hurricane forecasting, you know that in recent years, the European Center for Medium-Range Weather Forecasts has the best forecast model in the world based upon skill scores. Often, this intergovernmental organization of 34 nations produces the best forecasts for hurricane tracks.
In some cases, during Hurricane Harvey, it even exceeded the skill of human forecasters at the National Hurricane Center.
For this reason, the European model now has an outsized influence on the forecasts for hurricanes around the world, including those in the Atlantic, and in particular Hurricane Irma, which presently threatens the Caribbean Islands as well as the southeastern United States. How much influence? Take a look at this plot of a bunch of different models from Wednesday morning. Note the dark blue line on the left-hand side of the forecast tracks—that’s the official track forecast from the National Hurricane Center that was issued at 5am ET.
12z forecast model spaghetti plot for Hurricane Irma, with an official forecast track in dark blue. (credit: Weather Bell)
Now, you may be wondering, “why is the official forecast so far to the left, when all of the other models had moved east?” The answer is the European model.
This forecast system has superior hardware to run its calculations.
But more importantly it has a method by which it better assimilates real-world data—observations from weather networks around the world, atmospheric soundings, reconnaissance aircraft, and much more—into its calculations.
Read 9 remaining paragraphs