Contours of CAPE (Convective Available Potential Energy) which relates to energy available in the atmosphere for thunderstorm development. The 4 panel plot shows the 12, 24 (upper panels) and 36, 48 (lower panels) forecast.
4 Panel Helicity Forecast
Contours of Helicity which shows areas of shear or rotation with height. The 4 panel plot shows the 12, 24 (upper panels) and 36, 48 (lower panels) forecast.
4 Panel EHI Forecast
Contours of EHI which is a combination of CAPE and Helicity showing areas where strong or tornadic thunderstorms might develop. The 4 panel plot shows the 12, 24 (upper panels) and 36, 48 (lower panels) forecast.
48 hour Cumulative Precipitation Forecast
This is a plot of total precipitation over the 48 hour forecast.
48 hour Cumulative Snow Forecast
This is a plot of total snowfall over the 48 hour forecast. The estimates tend to be high for any snowfall over 2-3 inches since this doesn't take into account compaction and melting.
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.