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Weather forecast accuracy is a statistic anyone can measure and generate. Put the forecasts and the actual weather outcome together in a spreadsheet, examine th
by Afforess 10y ago
Weather forecast accuracy is a statistic anyone can measure and generate. Put the forecasts and the actual weather outcome together in a spreadsheet, examine the results each day for the 1,3, and 5 day forecasts. NOAA and the UK Met Office both do this for all of their forecasts, it's called "verification", and they measure their forecasting bias. In general, the statistics I've seen suggest the 1 day forecasts are 95% accurate, 3 day forecasts are ~80% accurate, and 5 day forecasts are ~70% accurate. This may vary if you live in a hard to forecast area.
For example, surface temperature forecast verification for Jan 2017: http://www.mdl.nws.noaa.gov/~verification/ndfd/index.php?mo_id=201701&ty_id=pt&rr_id=ptreray&re_id=co&wx_id=tt&pr_id=003&md_id=nd&mr_id=Array&cy_id=00&pd_id=ma http://www.mdl.nws.noaa.gov/~verification/ndfd/index.php?mo_...
- philippnagel 10y agoWhat constitutes a hard to forecast area? Any examples?
- Afforess 10y agoSure. The most challenging areas to forecast are typically areas with poor data availability (Mountains) or with topological features that impact the weather significantly (Great Lakes affect winter forecasts significantly). I imagine the Rocky Mountains and Great Lakes region both have lower than average forecast accuracy.
- ghaff 10y agoA lot of variability in weather. Multiple weather systems tending to come together. It's a lot harder to forecast Boston than it is Las Vegas. It also depends what you're trying to forecast. If you live in a very dry area, you're going to be right about precipitation the vast bulk of the time.
- pkaye 10y agoI've always wondered why so many weather websites make it hard to compare actual vs predicted weather forecasts for historical data.
- Cyphase 10y agoPossibly they don't want to make it easy to determine their accuracy rate.
- angry_octet 10y agoPeople are always happier being grumpy and ignorant than informed and accepting.
- Retric 10y agoThat does not seem like a great way to test for accuracy. ed: as described. I can predict Hawaii's temperatures out 20 years based on historical data much better than Chicago's. So some adjustment for area variability should be accounted for. People also care a lot more based on how off the temperatures are. So, being off by 5 degrees every day is better than being off by 1 degree for 4 days then 20 for the 5th. I assume there is some adjustments for this stuff?
- bdamm 10y agoYes. NOAA MOS does just this. http://www.nws.noaa.gov/mdl/synop/products.php http://www.nws.noaa.gov/mdl/synop/products.php