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Earth Books Supercomputing Idle

How The Advance Weather Forecast Got Good (npr.org) 80

NPR notes today's "supercomputer-driven" weather modelling can crunch huge amounts of data to accurately forecast the weather a week in advance -- pointing out that "a six-day weather forecast today is as good as a two-day forecast was in the 1970s."

Here's some highlights from their interview with Andrew Blum, author of The Weather Machine: A Journey Inside the Forecast : One of the things that's happened as the scale in the system has shifted to the computers is that it's no longer bound by past experience. It's no longer, the meteorologists say, "Well, this happened in the past, we can expect it to happen again." We're more ready for these new extremes because we're not held down by past expectations...

The models are really a kind of ongoing concern. ... They run ahead in time, and then every six hours or every 12 hours, they compare their own forecast with the latest observations. And so the models in reality are ... sort of dancing together, where the model makes a forecast and it's corrected slightly by the observations that are coming in...

It's definitely run by individual nations -- but individual nations with their systems tied together... It's a 150-year-old system of governments collaborating with each other as a global public good... The positive example from last month was with Cyclone Fani in India. And this was a very similar storm to one 20 years ago, that tens of thousands of people had died. This time around, the forecast came far enough in advance and with enough confidence that the Indian government was able to move a million people out of the way.

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How The Advance Weather Forecast Got Good

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  • by Anonymous Coward on Sunday June 30, 2019 @06:05PM (#58851946)

    It's not as simple as saying that governments work together. The US freely disseminates a very large amount of weather data and the source code to the models. There's GFS FV3 source code [github.com] on Github. WRF-ARW [ucar.edu] (the core used in the RAP and HRRR models) and WRF-NMM [dtcenter.org] (the core used in the NAM and NAM NEST models) are freely available, too. And when these models are run on NCEP supercomputers, the data are freely distributed on servers, limited only by the available bandwidth. Anyone can modify these models, and many people contribute new code to WRF. The open nature of these models allows anyone to run the models, to find and fix bugs, and to contribute improvements. An example is how researchers determined that radiative processes are really important to tropical cyclone forecasting [ametsoc.org] and eventually discovered there were significant bugs in operational models.

    Not everyone is so willing to share data and code, unfortunately. The gold standard in global models is the ECMWF model, developed by the European Centre for Mid-Range Weather Forecasting in Reading, UK. Unlike with the US models, they don't freely give their data or source code. Obtaining ECMWF data is actually quite expensive, which is unfortunate. While aspects of their model are discussed in scientific papers, one cannot readily access much of their data or obtain their source code.

    Although the US openly collaborates, sharing source code and data, not everyone is so willing to do so. While National Weather Service forecasters certainly can look at ECMWF data, a researcher in the US cannot so readily do so without paying quite a bit of money for it.

    • by ebh ( 116526 )

      Is it also true that part of what makes ECMWF so good is that they simply have more raw computing power than the US models have available to them?

  • Comment removed based on user account deletion
    • by Anonymous Coward

      Wait, you're complaining because they can predict thunderstorms but not tornadoes?

    • The standard of accuracy claimed is the 6 day forecast now is as good as the 2 day forecast in the 1970s. How good was tornado prediction two days in advance in the 1970s?
      • by Anonymous Coward

        There's no such thing as a two day tornado prediction. You can't even make a one day prediction. All meteorologists can report is whether conditions are right for storms that could produce tornadoes during that day, but not actually predict when or where they form.

    • by Anonymous Coward

      There are limits on our ability to produce accurate and skillful forecasts, in large part because the atmosphere is a chaotic system. A recent paper [ametsoc.org] suggested we may have reached the limit in accurately predicting tropical cyclone tracks. Generally speaking, skillful forecasts can be made at longer lead times for larger phenomena. A thunderstorm is a smaller scale process and, therefore, is more difficult to predict at longer lead times. Nonetheless, new models like the HRRR [noaa.gov] do a remarkably good job of

    • by geekoid ( 135745 )

      Do you understand what the number mean? seriously? 10% chance of rain doesn't mean rain on you.

  • Dude, git gud.
  • Even if it is minutes away like rain! :P Also, I noticed various forecasters show different results. :/

  • Apparently these so called scientist must live in a "normal" zone. Try forecasting the weather here in the southwest part of Missouri. The Missouri/Oklahoma/Kansas/Arkansas area is a PITA to forecast. The old saying here, is in the Ozarks, we have all four seasons....sometimes within TWENTY FOUR HOURS. I've seen Thunderstorms, hail & snow, within 12 hours. Once, I was heading north from Branson Missouri after a service call, and it was 53 degrees, but in Springfield Missouri, 30 miles north, it was free
    • Being on the North Coast usually means the weather report is worthless as well. Supposedly they recently began doing some additional offshore modeling (and improved the quality of water vapor modeling) but they're still getting it pretty seriously wrong.

    • by geekoid ( 135745 )

      "so called scientist"

      are you stupid?

      "Once, I was heading north from Branson Missouri after a service call, and it was 53 degrees, but in Springfield Missouri, 30 miles north, it was freezing rain."

      yep.

      Maybe actually learn about meteorology, resolution, the difference between where you ar at, and the area the forecast is for?

      The reason you d't get the is money. No one is pang a meteorologist to just do those areas, that are part of a wider area forecasted for.

  • despite the government throwing hundreds of millions of dollar at the weather agency for them to play with their supercomputer toys. If I only would get a single yen for each time they are wrong, I'd be a millionaire. We still have a long way to go....
  • I look at several different weather sites each day, more often than not the forecasts are not in agreement. Also I about three or four times a week I have coffee with group of fellow sorta seniors, we usually pull out the phones and compare forecasts, once in awhile they agree. Mostly when there is a major system moving in, other than that, the forecasters make their nickname of "weatherguessers" prophetic.
  • They still seem to do a very bad job estimation the severity and even the possibility of storms even the same day.
  • Comment removed based on user account deletion
  • They may be more precise, but they're not more accurate - or at least not that much more. A six-day forecast is pretty worthless at the moment.

  • by dcw3 ( 649211 ) on Monday July 01, 2019 @05:55AM (#58853816) Journal

    Until 5g fucks it up...

    https://physicsworld.com/a/deb... [physicsworld.com]

  • The old reliable standby. Forecasts up to a year in advance. Not just data points: wind speed, relative humidity, etc; but soul. How will you *feel* in New England when the humidity rises and the insects are buzzing all around you? And practical: When should you plant those azaleas or grimpin poggles?

    It's lovely that the billions spent on satellites and super computers can give us more detailed data, but the Farmers' Almanac gives us the Big Picture at a far more reasonable cost. And it's (almost) always ri

  • "Just as good..." Isn't there a TV ad campaign with that theme?
    Bottom line: there is no penalty for getting it wrong. If there were, they wouldn't be making predictions 7 days out. Also notice that the predictions change every day.

    • by geekoid ( 135745 )

      yes, there is a penalty, actually.

      The problem is, there isn't a penalty for idiots posting on sites about things they don't understand. As an example see: Your post.

  • "a six-day weather forecast today is as good as a two-day forecast was in the 1970s."

    you mean, total rubbish?

    in the 70's you couldn't trust the next day forecast, let alone two days.
    these days the next two days are pretty accurate, however 7 days is just not very reliable.

  • Weather in the Midwest is notoriously difficult to forecast, and it's only gotten worse lately. To get a forecast past two days you might as well just throw darts against a wall.
  • "a six-day weather forecast today is as good as a two-day forecast was in the 1970s ." If memory serves, the 70s were before weather satellites / Doppler radar was commonplace. If you give the good forecasters back then the /DATA/ we have today, we would have a better comparison of "accuracy"/benefit of the models. You can see from a graph from a previous /. article that at least hurricane prediction has only improved modestly since ~2003 ( https://science.sciencemag.org... [sciencemag.org] ) where most of the superco
  • 1. "got good" Seriously?

    2. The wx forecast didn't got good (sheesh) in my part of the country. Forecasters around here would have trouble forecasting yesterday's wx.

    3. I never believe anything NPR says, too much bias, too many lies and distortions.

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