Graphical Weather Products Chapter 9, Section D

Surface Analysis Chart Surface Analysis chart is a good source for general information over a large area. Shows position of fronts, temperature, dewpoint, wind at valid time of the chart When solid lines, called isobars, are close together the pressure gradient is greater and the winds are stronger A dashed line indicates a weak pressure gradient

Weather Depiction Chart Information on the chart is derived from the METAR reports Provides an overview of favorable and adverse weather Prepared every three hours A bracket symbol ] to the right of a station circle means it is an automated location

RADAR Summary Chart Only chart which shows lines and cell of thunderstorms You can determine the tops and bases of the echoes, the intensity of the precipitation and direction of movement Most effective when used in combination with other charts, reports, and forecasts

Terms Isopleths - used on precipitable water panel and are lines of equal value Isohumes - used on average relative humidity panel and are lines of equal relative humidity Isotherms - are lines of equal temperature Isotachs - are lines of equal wind velocity on Constant Pressure Analysis Charts

Graphic Forecasts Low-level Significant Weather Prognostic Chart is valid up to 400 millibars of pressure or about 24,000 feet Issued four time a day with a valid time printed on the lower margin of each panel Shows areas of IFR, MVFR, VFR and moderate or greater turbulence