Because of the limited overwater fetch, upstream moisture is likely an important variable in many events. There must be sufficient moisture for a parcel, lifted using traditional parcel methods, to reach a level of free convection. Moist convective updrafts must be sufficiently strong and deep to produce precipitation. A mechanism to lift parcels to their level of free convection must be present. The heaviest snowfall accumulations for lake-effect events will be found where the snowfall rate is greatest for the longest time.
Heavy snowfall can occur during short-lived events if the precipitation rate is high.
Examples include solitary wind-parallel bands that, in some events, can produce snowfall rates of 3 inches per hour. During longer-lived events, moderate snowfall rates can produce heavy accumulations. CAPE is relatively low and is consumed by moist convection almost as quickly as it is generated. Convection is preferentially initiated over the Great Salt Lake in the nighttime and early morning hours when localized heating over the lake produces land-breeze convergence. The post-frontal environment will not support moist convection.