Decatur, TX Tornado 10/12/01

We left Norman at 3:30 and drove south on I-35. Patrick Burke
called to let us know that the storms developing near SPS were
not as interesting as a supercell near Possum Kingdom Lake, so
we targeted that storm.

Another group of chasers, already on the PK Lake storm, gave
us a visual description of a non-tornadic supercell. It was
getting dark as we passed through Decatur, and headed south
on highway 51 to Springtown.

As we moved west of Agnes (on highway 199 NW of FTW), what appeared
to be a linear updraft base came into view. There was not
a lot of lightning, and the updraft appeared to be unorganized,
so we almost called it a day.

The other chase crew suddenly called to report the rapid
development of a rotating updraft east of Graford, to our
SW. Within a couple of minutes, a large circular updraft base
came into view to our SW. We moved east back to Agnes to let
it pass over highway 199.

A tornado warning was then announced for our storm. We decided
to re-position to the intersection of highways 51 and 114,
west of Boyd, believing the circulation would go west of
that intersection.

As we moved north, we paralleled the circulation. The lightning
increased dramatically, and we were able to watch the
eastern lip of a large, mostly rain wrapped circulation. The
base of the wall cloud was quite low to the ground.

Wall cloud image - taken during a 
lightning flash near
intersection of highways 51 and 114, west of Boyd, TX. View
is northwest. Note rain curtains wrapping around circulation.

After turning east on 114, just west of Boyd, we found a nice
hill top location to pull over. The wall cloud was to our
northwest by several miles, but quite evident in the frequent
lightning. The numerous lights of the city of Decatur were
plainly obvious even from our location 10 miles away.

The wall cloud contracted and the base of the wall cloud
dropped further and now appeared very low to the ground.
It also appeared that a clear slot was working into the
foreground. Suddenly, in a lightning flash, I thought I saw a
truncated cone funnel and debris cloud. By this time, the
circulation was getting pretty close to the lights of Decatur.

I became worried, but I was not yet convinced I had seen a
tornado. In another lightning flash, I saw the funnel and
possible debris cloud. Moments later, there was a bright
power flash in the same location.

I quickly dialed 911 to report a tornado moving into
Decatur. The power flashes suddenly became frequent near
the SW edge of the city lights, which suddenly disappeared.

For the next 6-7 minutes, I watched power flashes (sometimes
almost continuous) progress from west to east over Decatur.
After one power flash, there was a bright red glow that
persisted for several minutes.

There was enough rain wrapping around the circulation
to make the tornado invisible most of the time, but the
power flashes were quite brilliant.