Weather blog: are 90 day forecasts reliable? - WECT TV6-WECT.com:News, weather & sports Wilmington, NC

Weather blog: are 90 day forecasts reliable?

Forecasts have greatly improved in the last several days, but are they good enough to go further out than the traditional 7 days? (Source: WECT) Forecasts have greatly improved in the last several days, but are they good enough to go further out than the traditional 7 days? (Source: WECT)
The forecast from April 6th, 2016 for Independence Day in Wilmington calls for clouds and a 60% chance of storms. (Source: Accuweather) The forecast from April 6th, 2016 for Independence Day in Wilmington calls for clouds and a 60% chance of storms. (Source: Accuweather)
The April 11th, 2016 for Independence Day in Wilmington called for sunny skies. (Source: Accuweather) The April 11th, 2016 for Independence Day in Wilmington called for sunny skies. (Source: Accuweather)

The science of meteorology has become much more advanced in its technology and accuracy in recent years. 

We've seen significant improvement in the past five years to global weather models with upgrades to the GFS (Global Forecast System) and the ECMWF (European Centre for Medium-Range Weather Forecasting) and radar technology. 

But even with these improvements and upgrades, how well has the forecasting become? The GFS can forecast out 16 days into the future, but how reliable is that 16 day forecast?

Accuracy in forecast within three days of the initial forecast; with an 85 percent probability of the forecast being right. Between three and seven days, accuracy does diminish, to around 60 percent. But the further out you get from the initialization point of a model, the data gets blurrier and blurrier.

Large scale pattern can be well modeled during this 16 day period, but sensible weather is hard to pinpoint much after seven days due to the volatility of the science. 

In August 2013, Accuweather, a private weather forecasting company, introduced a 45 day forecast product. This was met with some controversy in the weather enterprise. Recently, Accuweather unveiled a new 90 day forecast product.

With the limitations of the science, namely in sensible weather forecasting, how can this be? The longest range synoptic model only goes out 16 days and even that is sketchy at best. 

Many in the weather community has criticized this move because it lacks transparency of the data sources and could be a disservice. 

The issue is, there is a market for these long range forecasts. 

People who want to plan weddings, plan trips or just general curiosity, the market exists. Most people see these and realize to take it with a grain of salt; others could take it to heart and make major decisions based off these wildly variable forecasts.

For instance, on April 6, 2016, the forecast for Wilmington for July 4 called for it to be "mostly cloudy and humid with a shower or thunderstorm around." The high: 86 degrees with a 60 percent chance of storms. The forecast from April 11, 2016 for July 4 calls for "sunny skies" and a high of 89 degrees. 

Both forecasts seem plausible, considering the time of the year. 

So will you cancel your plans or let them ride? Only time will tell what will happen in 85 days; we'll make sure to give you our thoughts on Independence Day in about 78 days. 

Copyright 2016 WECT. All rights reserved. 

  • First Alert Weather NewsFirst Alert Weather NewsMore>>

  • First Alert Forecast: settled weather, at long last, to grace the area Friday

    First Alert Forecast: settled weather, at long last, to grace the area Friday

    Friday, May 26 2017 4:37 AM EDT2017-05-26 08:37:40 GMT

    A high pressure system will bring a pleasant, tranquil, and dry ending to what's been, overall, a very wet and stormy work week.

    More >>

    A high pressure system will bring a pleasant, tranquil, and dry ending to what's been, overall, a very wet and stormy work week.

    More >>
  • NOAA releases 2017 Atlantic Hurricane Season forecast

    NOAA releases 2017 Atlantic Hurricane Season forecast

    Thursday, May 25 2017 12:29 PM EDT2017-05-25 16:29:18 GMT

    NOAA - the National Oceanic and Atmospheric Administration - released its 2017 Hurricane Season forecast for the Atlantic Basin Thursday.

    More >>

    NOAA - the National Oceanic and Atmospheric Administration - released its 2017 Hurricane Season forecast for the Atlantic Basin Thursday.

    More >>
  • Hurricane cone-ology

    Hurricane cone-ology

    Today, satellites and supercomputers have vastly improved hurricane forecasting and warning. But one of our age's best tools for communicating a hurricane threat, the National Hurricane Center's official “forecast cone," can be misrepresented and is often misunderstood.

    More >>

    Today, satellites and supercomputers have vastly improved hurricane forecasting and warning. But one of our age's best tools for communicating a hurricane threat, the National Hurricane Center's official “forecast cone," can be misrepresented and is often misunderstood.

    More >>
Powered by Frankly