THE JUNE 4TH 1995 MULTIPLE SIMULTANEOUS
LANDSPOUTS
Peter Blottman and Daniel Padavona
National Weather Service Office
32 Dawes Drive
Johnson City, New York 13790
Peter.blottman@noaa.gov
(607) 770-9531
fax (607) 798-6624
An observational study is presented of an unusual multiple simultaneous landspout (non
supercell tornado) event that occurred along merging boundaries in the Texas Panhandle on 4
June 1995. WSR-88D radar, satellite, sounding and surface data sets as well as video have
been used to document the development and evolution of this event. Shortly after an eastward
moving dryline and a westward moving convective outflow boundary collided a series of
landspout tornadoes developed, followed 45 minutes later by the development of a
mesocyclone induced tornado. The boundary collision played a key role in the landspout
development. Analyses suggest that the merging boundaries served to enhance low level
convergence and convective updraft speed at the occlusion point, thereby assisting vortex tube
stretching a necessary component in the formation of landspouts (Wakimoto 1989, and Brady
and Szoke 1989). The multiple landspouts appeared to develop sequentially at the occlusion
point between the two boundaries. Additionally, horizontal vorticity along the leading edge of
the westward propagating outflow boundary may have further strengthened the vortices as the
streamwise vorticity was tilted into the vertical. A comparison of this case to the numerical
simulation of multiple landspouts by Lee and Wilhelmson (1997) is presented.