Waterspout · Lake Erie

Waterspout spotted offshore Walnut Creek Marina in Fairview. Location of waterspout estimated.

A line of towering cumulus clouds accompanied a surface trough axis that drifted generally southward across Lake Erie during the late afternoon and early evening of the 27th. Warming and moistening of an unusually-cool low-level air mass over Lake Erie yielded lake-induced instability. Horizontal wind shear along the surface trough axis likely induced surface-based vertical vorticity. This surface-based vertical vorticity was likely ingested by the updraft of a towering cumulus cloud, stretched to tornado-strength via low-level convergence at the base of the updraft, and was then advected upward in the updraft, allowing a waterspout to form offshore Erie County, PA.