THUNDERSTORMS AND
TORNADOES
by
Ernest M. Agee
An aerial view of a classic supercell thunderstorm above southern
Maryland on 29 April 2002. At the time this photograph was taken this
storm was producing twin tornadoes.
Two mini-tornado cyclones and associated
wall clouds in Fort Cobb, Oklahoma.
Two mini-tornado cyclones each producing a single
vortex tornado near Canadian, Texas (7 May 1986).
Colby, Kansas, 21 July 1996
Multiple vortex tornado, Tm, near Friendship, Oklahoma (May 1982).
Multiple vortex columns in the formative stages of the
Jarrell, Texas tornado of 27 May 1997.
Left: Radar image from the Quad Cities containing two supercells with
well defined hook echoes (5:00 pm; 4/30/03).
Right: Radar image from Tulsa, OK containing a squall line with
embedded supercells ( 6:25 pm; 5/6/03).
Left: Radar image from San Angelo of squall line with bow echo and
embedded supercells (4:30 pm; 4/7/02).
Right: Radar image from Freederick, OK containing a supercell well
defined hook echo (3:00 pm: 3/17/03).
Left: Radar image from Dallas/Forth Worth containing three supercells
all with well defined hook echoes (9:20 pm; 4/5/03).
Right: Radar image from Frederick, OK containing a supercell with a
well defined hook echo (5:08 pm; 4/5/03).
First radar tracking of a tornado’s hook echo.
A Doppler radar image of a supercell thunderstorm near Oklahoma City on
3 May 1999. The image on the left shows a nice example of a hook
echo radar feature that sometimes accompanies the mesocyclone. The
image on the right shows the indication of the TVS, identified by ▼.
Horizontal flow relative to moving storm at 6.4 km above ground. Lengths
of arrows are proportional to relative wind speed.