Prognostic chart the correct location. By 1957, it was proposed when isobars or height lines at the pressure level in the atmosphere were being verified, that the degree of persistence should be considered so as to avoid getting bad forecasts for slow moving systems too much credit. Prognostic chart A prognostic chart is a map displaying the likely weather forecast for a future time. Such charts generated by atmospheric models as output from numerical weather prediction and contain a variety of information such as temperature, wind, precipitation and weather fronts. They can also indicate derived atmospheric fields such as vorticity, stability indices,
Prognostic chart charts generated by computer models are sometimes referred to as machine-made forecasts. Surface weather prognostic charts for mariners indicate the positions of high and low pressure areas, as well as frontal zones, up to five days into the future. Surface wind direction and speed is also forecast on this type of chart. Wave prognostic charts show the expected sea state at some future time. Low-level prognostic charts used by aviators show the forecast between the Earth's surface and above sea level over the next two days. They show areas where visual flight rules are in effect, instrument flight rules are