Helicity in itself is not the only component of severe thunderstorms and those values are to be taken with caution. That is why the Energy Helicity Index (EHI) has been created. It is the result of SRH multiplied by the CAPE (Convective Available Potential Energy) and then divided by a threshold CAPE: EHI = (CAPE x SRH) / 160,000. This incorporates not only the helicity but the energy of the air parcel and thus tries to eliminate weak potential for thunderstorms even in strong SRH regions. The critical values of EHI:
EHI = 1 ... possible tornadoes
EHI = 1-2 ... moderate to strong tornadoes
EHI > 2 ... strong tornadoes
Ik zie hier op het kaartje EHI van 4.2. M.a.w. grote kans op 'strong tornadoes'? Quote selectie
