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The Union County Landspout

9 June 2001

Bryan P. McAvoy
NOAA/National Weather Service
Greer, SC

Tornado near Carlisle, SC, on 9 June 2001.  Image provided by Tony Henderson.

A weak tornado touched down near Carlisle, South Carolina, on 9 June 2001. Image taken by Tony Henderson.

Author's Note: The following report has not been subjected to the scientific peer review process.

1.  Introduction
During the afternoon of June 9, 2001, a weak tornado occurred 
in southern Union County, South Carolina.  The tornado touched 
down around 330 pm EDT (1930 UTC), about 3 miles west southwest 
of Carlisle, in the heart of the Sumter National Forest, and 
dissipated a few minutes after 4 pm.  The damage path was never 
surveyed, but local fire and rescue reported some minor tree 
damage where the tornado went into the woods. 
2.  Discussion 
When we say "tornado", we do not mean the classic supercell 
tornado, which forms over a depth of thousands of feet and can 
produce catastrophic damage.  In this case, the tornado was one 
that is usually classified as a "landspout".  The phrase is 
derived from the more common "waterspout" which is a weak 
tornado that forms over water, and is seldom if ever associated 
with a parent mesocyclone.

In the case of the Union County tornado, it occurred in a fairly 
typical landspout environment.  The associated convection was 
very weak, not more than a moderate shower.  The radar four 
panels (Fig. 1) show the reflectivity pattern from 0.5, 1.5, 
2.4 and 3.4 degree elevation scans.  In other words, these images 
were taken at the same time, but at different elevations in the 
storm.  Notice how small and weak the cell is.  The storm top, 
in the fourth panel (lower right), does not even extend to 
20,000 feet, and these images represent the storm at its 
strongest.  The storm relative velocity data from the same time 
(Fig. 2) show no organized areas of rotation, nor any strong 
storm top divergence. 
KGSP base reflectivity at 1948 UTC 9 June 2001
Figure 1.  KGSP radar reflectivity at 1948 UTC 9 June 2001 at 
0.5 degrees (upper left), 1.5 degrees (upper right), 2.4 degrees 
(lower left), and 3.4 degrees (lower right).
KGSP storm relative motion at 1948 UTC 9 June 2001
Figure 2.  As in Fig. 1, except for Storm Relative Motion.


This is typical of a landspout as all the dynamics for the 
tornado occur very low in the atmosphere, below the cloud base.  
As a result, the Weather Surveillance Radar (WSR-88D) at the
National Weather Service office at the GSP airport could not
effectively scan these features, as they occur too low in the 
atmosphere and on too small a scale for the beam to detect 
them at long range.
But, there most definitely was a tornado.  Witnesses watched 
the landspout for nearly 30 minutes.  In fact one witness, 
Tony Henderson, even took pictures (Fig. 3).
Tornado over Union County, SC, near Carlisle.  Image taken by Tony Henderson
Figure 3.  Image of weak tornado over Union County, South
Carolina, near Carlisle.  Image taken by Tony Henderson.
During its life, the landspout was nearly stationary, drifting 
only slowly to the southeast.  This is a typical characteristic 
of landspouts.  Landspouts are usually stationary as they form 
in a weakly sheared environment, which is anathema to other 
types of tornado production.  Witnesses said there was very 
little rain and no lightning and thunder, another landspout 
characteristic.  The evening sounding from nearby Greensboro, 
North Carolina, had weak lower tropospheric shear, though winds 
increased aloft.
Essentially, a landspout forms when a broad, weak area of 
cyclonic or anticyclonic rotation in the low levels of the 
atmosphere is caught up in the updraft of a developing cumulus 
cloud.  The effect is similar to that of a figure-skater pulling 
in her arms to spin faster.  As the area of rotation is stretched 
and constricts, it rotates faster, until condensation occurs and 
the funnel become visible.  In this case, the landspout was 
frequently in contact with the ground.  Thus, by definition, 
it was a tornado.


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