What Goes Into Hurricane Forecasting? Satellites, Supercomputers And More

2017-09-11T14:44:36+00:00 September 11, 2017|

Satellite view of Hurricane Irma on September 3, 2017. Photo credit: NASA

Where will it go? How strong will it be? When will it hit? Those are the answers everyone wants — not the least of which are the hurricane forecasters themselves.

(From NPR.org/ by Scott Neuman) — To get those answers, hundreds of millions of data points — everything from wind speeds to sea temperatures — pouring in from satellites, aircraft, balloons, buoys and ground stations are fed into the world’s fastest computers and programmed with a variety of models at different resolutions, some looking at the big picture, others zooming in much closer.

That data, collected by the National Oceanic and Atmospheric Administration and other forecast agencies around the globe, is processed and ends up on local weather reports.

“We have a whole suite of numerical forecast models ranging from those at the global scale, that have less spatial resolution, to other models that cover smaller domains, but have higher resolution,” Christopher Velden, a senior researcher at the University of Wisconsin, Madison’s Space Science and Engineering Center, tells NPR.

The advent of supercomputers and the more complex models they can accommodate has meant a revolution in forecasting as ever-more granular data can be packed into the input, Velden says.

“In the past, there was an incredible amount of satellite data that just dropped on the floor because we simply didn’t know how to effectively ingest it all into the models,” he says. “Now, with advanced data assimilation systems and supercomputing, more of the information content of that data is making it into the models, and improving forecasts.”

The best known global-scale models are the European Center for Medium Range Weather Forecasting Model, or ECMWF, and Global Forecast System, or GFS, run by NOAA’s National Centers for Environmental Prediction. Those models are used for all kinds of weather forecasting, not just hurricanes, so if you are something of a weather geek, you’ve no doubt encountered them before.

These two models, and a handful of others, are good at making predictions in forecasting hurricanes, especially where they will go.

“The best hurricane forecasting models we have are ‘global’ models that solve the mathematical equations governing the behavior of the atmosphere at every point on the globe,” writes Jeff Masters, the director of meteorology at Weather Underground. “These models take several hours to run on the world’s most advanced supercomputers.”

The GFS and ECMWF models are run every six to 12 hours, but the more focused models, which have higher resolution and in some cases feed off near-real-time data, are run every three to six hours, according to Velden.

Read the full story here: http://www.npr.org/sections/thetwo-way/2017/09/08/549477502/what-goes-into-hurricane-forecasting-satellites-supercomputers-and-more