@article{koch_hamilton_kramer_langmaid_1998, title={Mesoscale dynamics in the Palm Sunday tornado outbreak}, volume={126}, ISSN={["1520-0493"]}, DOI={10.1175/1520-0493(1998)126<2031:MDITPS>2.0.CO;2}, abstractNote={Abstract Radar and satellite imagery suggest that strong mesoscale forcing occurred in the Palm Sunday tornado outbreak on 27 March 1994. Parallel lines of severe thunderstorms within each of three mesoscale convective systems developed just ahead of a cold front in Mississippi and Alabama on this date. Analyses of routine meteorological observations, barograph data, and forecasts from the Eta and NGM models and a mesoscale research model (MASS) are used to examine the relative roles of large-scale dynamics and mesoscale processes in triggering and organizing the mesoscale convection. Quasigeostrophic forcing was absent in the outbreak region. Likewise, a thermally direct circulation system transverse to the upper-level jet that was present to the northwest of the outbreak region was decoupled from the strong low-level ascent occurring in northern Alabama and Mississippi at the time of the outbreak. Strong ageostrophic frontogenesis in the presence of conditional symmetric instability (CSI) was the chief ...}, number={8}, journal={MONTHLY WEATHER REVIEW}, author={Koch, SE and Hamilton, D and Kramer, D and Langmaid, A}, year={1998}, month={Aug}, pages={2031–2060} }
 @article{langmaid_riordan_1998, title={Surface mesoscale processes during the 1994 Palm Sunday tornado outbreak}, volume={126}, ISSN={["0027-0644"]}, DOI={10.1175/1520-0493(1998)126<2117:SMPDTP>2.0.CO;2}, abstractNote={The tornadic storms that developed in the 27 March 1994 Palm Sunday outbreak were confined to a narrow zone extending from central and northern Alabama to western North Carolina. Analysis of surface observations and soundings is used to examine the mesoscale environment of the region starting 14 h prior to storm development. The evolution of a shallow front that formed the northern boundary of the outbreak region is tied to several diabatic processes including evaporation of precipitation and differential solar heating. The resulting front was found to both limit severe convection and focus supercell development later in the day. During the night before the outbreak, as copious widespread precipitation fell into dry air, evaporation maintained a cold air pool north of the front. By contrast, moderate southerly flow provided warm, moist conditions to the south. Precipitation-enhanced cold air damming along the eastern slopes of the Appalachians also may have provided a source of cold air for subsequent frontogenesis over areas farther west. During the daylight hours, differential solar heating across the front further enhanced frontogenesis. Intensification of convection just prior to the first tornadoes was found to be associated with areas of breaks in the overcast near and upstream of tornadogenesis. Similarly, cells that intensified were moving over a surface that had been thoroughly moistened by previous rainfall. Supercells that intersected and moved along the frontal boundary maintained their tornadic strength for many hours, whereas storms that crossed the boundary disintegrated. Blockage of inflow by upstream storm cells may also have contributed to the rapid reduction of intensity of one of the tornadic cells.}, number={8}, journal={MONTHLY WEATHER REVIEW}, author={Langmaid, AH and Riordan, AJ}, year={1998}, month={Aug}, pages={2117–2132} }