This plot shows forecasted surface conditions at a particular forecast time for several major cities. The plot contains a contour analysis of 12 hour quantitative precipitation and station model plots of surface conditions for the valid time.
NAM MOS Weather Depiction Plots
This plot shows forecasted weather depiction charts used in aviation. The data plotted are cloud cover, forecast weather, cloud ceiling.
0 - 3000m Helicity
Helicity is used to indicate where rotation/shear is high enough to allow thunderstorms to organize into severe or supercell storms. In the lack of helicity, storms develop vertically and the precipitation will snuff out the updraft killing the thunderstorm. Severe storms need helicity to maintain an organized structure allowing hte storm to develop to severe limits. A value of 400-500 is often needed to produce severe storms. Often this is used in conjunction with CAPE to determine severe storm location.