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NOAA Goes Live With New Forecasting Supercomputers

Posted by samzenpus on from the better-reports dept.

dcblogs writes "The National Oceanic and Atmospheric Administration (NOAA) Thursday switched on two new supercomputers that are expected to improve weather forecasting. The supercomputers are each 213 teraflops systems, running a Linux operating system on Intel processors. The U.S. is paying about $20 million a year to operate the leased systems. The NWS has a new hurricane model, Hurricane Weather Research and Forecasting (HWRF), which is 15% more accurate in day five of a forecast both for forecast track and intensity. That model is now operational and running on the new systems. In nine month, NWS expects to improve the resolution of the system from 27 kilometers to 13 kilometers. The European system, credited with doing a better job at predicting Sandy's path, is at 16 kilometers resolution. In June, the European forecasting agency said it had a deal to buy Cray systems capable of petascale performance."

2 of 53 comments (clear)

  1. Huh? Awful article summary... by Bud+Light+Lime · · Score: 5, Interesting

    HWRF runs at a much finer grid spacing than 27 or 13 kilometers. As I recall, the grid spacing is around 3 km in the inner nest. This is done to explicitly simulate the convection at the inner core of a tropical cyclone. This nest moves with the storm, and is embedded within a much larger domain. The upgrade from 27 to 13 kilometers actually refers to the GFS model. It's a spectral model that has a global domain. Other models that are regional (including the outer domain of the HWRF) need to know the conditions at their lateral boundaries, so they know what's moving into the domain. In the US, they typically use the GFS for their boundary conditions. I'm actually very skeptical of the need for upgrading the resolution of the GFS. That may have a role in improving GFS forecasts, but there have been studies showing that the initial conditions of the GFS are the real problem. The atmosphere is a chaotic system; that is, two similar initial states will diverge over time to produce two very different outcomes. In a study where the GFS was initialized with ECMWF initial conditions, the performance of the GFS improved. Hurricanes are typically steered by large scale features, which aren't necessarily going to be simulated better by using a finer resolution. It also doesn't address the initial conditions problem. I'm in favor of throwing more computing power at meteorology, but I'm not convinced it will solve the problems with the GFS.

    1. Re:Huh? Awful article summary... by Bud+Light+Lime · · Score: 3, Interesting

      Your point about the GFS is well-taken, but at present, I'd never use the GFS or ECMWF to forecast hurricane intensity. Yes, there's value in increasing the resolution of the model. But there's also a need to improve the data assimilation to produce better initial conditions (see this NOAA white paper). The conclusion was that there are gains to be made by bumping up the resolution, but that's only one of the recommended approaches to improving the GFS. Others included better data assimilation and improving parameterizations. Much of what the public hears has been focused on the resolution of the model. Yes, it does matter, but there are other considerations that are at least equally important.

      Much of the criticism of the GFS with respect to Sandy has focused on the track forecast several days out. While increasing the resolution of the model could provide some improvement to the track forecasts, I would expect better initialization to have a larger role, especially at that forecast range. I'd believe bumping up the resolution would provide much better gains in the area of forecasting intensity.