The impact of superimposed low-level jets during the 2003 Presidents' Day winter storm

During the second Presidents' Day winter storm of 15-18 February 2003, snowfall totals exceeding 100 cm were reported across a relatively small region of western Maryland and northeastern West Virginia. This numerical modeling study considers the role of two juxtaposed low-level jet/front systems, the continental and maritime, in the generation of extreme snowfall. Results indicate that frontal lifting, reinforced by intense frontogenesis, was the source of narrow bands of strong lift over the region. Confluent deformation, resulting from interaction between the continental and maritime low-level jets, produced locally steeper slopes of the continental front with the continental jet forced up these steep frontal inclines. Additional impacts of the juxtapositioning of the two low-level jets, such as inertia-gravity wave generation and orographic enhancement of snowfall, are briefly discussed.