However these graphics provide a good starting point for a weather briefing. Frames are 6 hours apart out to a 60 hour forecast. Yellow lines represent the height of the 500 Mb surface above sea level in decameters. The height field depicts the ridge and trough systems aloft which largely determine the surface weather. The vertical bar on the left indicates the colors for different ranges of relative humidity.
Red contours are isolines of accumulated precipitation, labeled in hundreths of an inch.
Precipitation for each frame accumulated in the 6 hours before the valid time. Vectors represent the direction and relative speed of the 700 Mb wind. The contours and color shading are temperatures in degrees Fahrenheit. The color-bar on the left shows the range of temperatures for each color. Frames are 6 hours apart out to a 120 hour forecast time.