Enter a ZIP code to get a forecast:
Setup Location

WRN Logo

Helicity - Current Inverted

Please take our Weather website Usage Survey
Note: This survey is hosted on Survey Monkey servers. Clicking the survey link above will direct you outside our network to the Unisys-approved survey page on the Survey Monkey website. We respect your privacy in accordance with our Privacy Notice.
Helicity - Current Inverted
Click On the Image For Full Size.

This is a contour plot of helicity which is the amount of storm relative rotation/shear in the atmosphere. 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 the 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.