Snow Squalls May Impact New Year's Eve Travel from the Great Lakes to the Mid-Atlantic; Heavy Rain & Isolated Severe Thunderstorms in Southern California

Snow squalls are likely to cross the Lower Great Lakes this evening and the Ohio Valley through the interior Northeast/northern Mid-Atlantic overnight, before potentially reaching the I-95 corridor from D.C. to New York City early New Year’s Day morning. Heavy rain and isolated severe thunderstorms will impact coastal southern California including Los Angeles tonight into early on New Year's Day. Read More >

February 20-21, 2014
Severe Weather, Tornadoes, and Flooding

A quasi-linear convective system (QLCS) developed ahead of a rapidly deepening low pressure system moving across the mid-west. This line produced sporadic damaging winds as it crossed the Wilmington, OH forecast area. Bowing and broken-s radar signatures appeared along the line of convection which became the focus of 3 tornado spin-ups as well as small scale enhanced straight line wind damage.

A discrete cell developed just ahead of the main line of convection in southeastern Indiana. This cell began to rotate aloft with this rotation quickly translating to the surface in just a few minutes. An EF1 tornado touched down in Ripley, County Indiana as a result of this circulation. The cell then got absorbed by the pursuing line of convection.
A broken-s signature developed as the line entered west central Ohio. This segment eventually produced an EF-0 tornado in Montgomery County
The QLCS began to weaken as it moved into a more stable airmass across central Ohio during the middle of the night. However, wind shear was still very strong, and was sufficient to bring a weak circulation briefly to the surface in Delaware County in the form of an EF0 tornado.
Snow melt that had been occurring leading up to the event had already produced areas of standing water over frozen ground. Rain from this system added to the runoff from the melted snow, resulting in minor flooding across the area.