|  | P1.1 | The maintenance of severe mesoscale convective systems through the southern Appalachians: favorable vs. unfavorable environments
Stephen J. Keighton, NOAA/NWS, Blacksburg, VA; and J. Jackson and W. Perry |
| | P1.2 | The 10–11 April 2001 late night tornado outbreak along a squall line in south central Nebraska/north central Kansas
Rick Ewald, NOAA/NWS, Hastings, NE; and D. D. Nietfeld |
| | P1.3 | Radar Survey of Mesoscale Convective System Development 
Israel L. Jirak, Colorado State University, Fort Collins, CO; and W. R. Cotton and R. L. McAnelly |
| | P1.4 | The Structure and Dynamics of Moist Absolutely Unstable Layers in Simulated Squall Lines
George H. Bryan, Penn State Univ., University Park, PA; and J. M. Fritsch |
| | P1.5 | Evolution of a mesoscale convective vortex over Northern Arizona
David O. Blanchard, NOAA/NWS, Flagstaff, AZ |
| | P1.6 | A preliminary investigation of derecho-producing MCSs over the central and eastern United States in environments of very low dewpoints
Stephen F. Corfidi, NOAA/NSSL/SPC, Norman, OK |
| | P1.7 | A preliminary comparison between convectively generated mesoscale vortices in the United States and in China
Jason C. Knievel, NCAR, Boulder, CO |
| | P1.8 | A turn of events for a long-lived convective system
John D. Tuttle, NCAR, Boulder, CO; and R. E. Carbone |