Weather Graphic Products Surface Analysis Chart Surface Analysis

Weather Graphic Products

Surface Analysis Chart • Surface Analysis - Shows fronts, data such as temperature, dewpoint, & wind Solid lines, called isobars, close together, indicate pressure gradient is greater and winds are stronger A dashed line indicates a weaker pressure gradient

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

RADAR-Summary Chart • Shows lines and cell of thunderstorms • Numbers indicate the height of the tops and bases of the echoes. The intensity of the precipitation and direction of movement is also provided. • Use in combination with other weather charts, reports, and forecasts

Analytical Terms • Isopleths – lines of equal value, used on precipitable water panels • Isohumes – lines of equal humidity, used on average relative humidity panels • Isotherms - lines of equal temperature • Isotachs - lines of equal wind velocity on Constant Pressure Analysis Charts

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