These hyper-extended forecasts have been compared to actual results several times and shown to be misleading, inaccurate and sometimes less accurate than simple predictions based on National Weather Service averages over a 30-year period.[19][20] It is generally accepted that the upper limit on how far one can reliably forecast is between one and two weeks, a limit based on both limits in observation systems and the chaotic nature of the atmosphere.[19][21][22] An informal assessment conducted by Jason Samenow at The Washington Post asserted that AccuWeather's forecasts at the 25-day range were often wrong by as many as ten degrees, no better than random chance and that the forecasts missed half of the fourteen days of rain that had occurred during the month of the assessment.[23] AccuWeather responds that it does not claim absolute precision in such extremely long forecasts and advises users to only use the forecast to observe general trends in the forecast period,[24] but this contrasts with the way the forecasts are presented.[25] An assessment from the Post determined that the 45-day forecasts were not even able to predict trends accurately, and that, although the forecasts did not decrease in accuracy with time, the forecasts were so far off even in the short range as to be useless.[25] The Post commissioned another assessment from Penn State University professor Jon Nese, comparing several more cities to Accuweather's predictions; that assessment, while acknowledged as being limited to a single season, acknowledged that AccuWeather's forecasts were of value in short-range forecasting while also noting that their long-range forecasts beyond one week were less accurate than climatological averages.[20]