You have your choice of sources of weather forecasts on various smartphone apps and web pages.
Where can you get the best forecast? (other than this blog, of course 😊)
One service, Forecastadviser.com, evaluates predictions from many weather outlets, including the National Weather Service to the Weather Channel (Weather.com).
Consider the scores for the last year (2022) for Seattle considering 5-day forecasts. The Weather Channel is number one, followed by Accuweatther. The National Weather Service is way down the list!.
How about Chicago? Pretty much the same thing. In fact, most cities are similar.
Microsoft has a new forecast system, part of their Microsoft Start effort, that has moved up rapidly to third or fourth place. During the past month, it has been number one in some cities.
In contrast, the National Weather Service is lagging pretty much everywhere.
So why are many commercial services, whose forecasts are entirely automated, doing so much better than the Weather Service, which includes human forecasts in the loop?
These superior systems start with global observations and forecasts from many different forecast models, such as the European Center and U.S. GFS global models. Using a history of observations and model forecasts, the advanced systems then create statistical models that combine the various inputs to produce forecasts with lower typical errors.
Many of the newest systems, such as the Microsoft Start system, make use of sophisticated machine learning approaches to optimally combine the available observations and models. This process needs to be done at every forecast location, so the amount of computation is not trivial.
With better and better models and more and more observations, these objective forecasts have gotten very good.
So why is the National Weather Service lagging?
National Weather Service forecasters start with the Weather Service’s own system for combining forecasts: the National Blend of Models (NBM), which is not as sophisticated or capable as the one used by corporate systems (such as IBM’s weather.com). For five-day forecasts, humans add little value…sorry, but that is the truth.
Other verification comparisons show little improvement of NWS forecasters on shorter periods forecasts as well.
Do I have a weather app do I have on my smartphone? I have to admit: I do.
The WeatherChannel.
Can I beat the forecast of the Weather Channel? Yes, perhaps half the time, using the higher resolution UW modeling system and an intimate knowledge of the local weather. But not always, particularly for run-of-the-mill weather situations.
The days of human forecasters will soon be over. However, human forecasters still have a vital role to play in communicating the forecasts and helping local governments and others to make optimal use of computer-based predictions.
