This is a set of contour plots using data from the GFS model. The output fields are consistent with other models so the models can be compared. This model gives forecast information out to 240 hours and plots are 48 and 96 hour 4 panel plots where each plot has a panel data for a specific forecast time (12-48 and 60-96 hrs) and individual forecast times from initialization to 240 hours in 12 hour increments. These plots are updated every 12 hours at roughly 0500 UTC and 1700 UTC.
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.