THUNDERSTORMS AND THUNDERSTORMS AND TORNADOESTORNADOES

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Ernest M. Agee Ernest M. Agee

An aerial view of a classic supercell thunderstorm above southern An aerial view of a classic supercell thunderstorm above southern Maryland on 29 April 2002. At the time this photograph was taken this Maryland on 29 April 2002. At the time this photograph was taken this

storm was producing twin tornadoes. storm was producing twin tornadoes.

Two mini-tornado cyclones and associated Two mini-tornado cyclones and associated wall clouds in Fort Cobb, Oklahoma.wall clouds in Fort Cobb, Oklahoma.

Two mini-tornado cyclones each producing a singleTwo mini-tornado cyclones each producing a singlevortex tornado near Canadian, Texas (7 May 1986).vortex tornado near Canadian, Texas (7 May 1986).

Colby, Kansas, 21 July 1996Colby, Kansas, 21 July 1996

Multiple vortex tornado, TMultiple vortex tornado, Tmm, near Friendship, Oklahoma (May 1982)., near Friendship, Oklahoma (May 1982).

Multiple vortex columns in the formative stages of the Multiple vortex columns in the formative stages of the Jarrell, Texas tornado of 27 May 1997.Jarrell, Texas tornado of 27 May 1997.

Left: Radar image from the Quad Cities containing two supercells with Left: Radar image from the Quad Cities containing two supercells with well defined hook echoes (5:00 pm; 4/30/03).well defined hook echoes (5:00 pm; 4/30/03).

Right: Radar image from Tulsa, OK containing a squall line with Right: Radar image from Tulsa, OK containing a squall line with embedded supercells ( 6:25 pm; 5/6/03). embedded supercells ( 6:25 pm; 5/6/03).

Left: Radar image from San Angelo of squall line with bow echo and Left: Radar image from San Angelo of squall line with bow echo and embedded supercells (4:30 pm; 4/7/02).embedded supercells (4:30 pm; 4/7/02).

Right: Radar image from Freederick, OK containing a supercell well Right: Radar image from Freederick, OK containing a supercell well defined hook echo (3:00 pm: 3/17/03).defined hook echo (3:00 pm: 3/17/03).

Left: Radar image from Dallas/Forth Worth containing three supercells Left: Radar image from Dallas/Forth Worth containing three supercells all with well defined hook echoes (9:20 pm; 4/5/03).all with well defined hook echoes (9:20 pm; 4/5/03).

Right: Radar image from Frederick, OK containing a supercell with a Right: Radar image from Frederick, OK containing a supercell with a well defined hook echo (5:08 pm; 4/5/03).well defined hook echo (5:08 pm; 4/5/03).

First radar tracking of a tornado’s hook echo.First radar tracking of a tornado’s hook echo.

A Doppler radar image of a supercell thunderstorm near Oklahoma City 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 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 echo radar feature that sometimes accompanies the mesocyclone. The

image on the right shows the indication of the TVS, identified by ▼. 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 Horizontal flow relative to moving storm at 6.4 km above ground. Lengths of arrows are proportional to relative wind speed.of arrows are proportional to relative wind speed.