Initial view of the storm: plain, dark shelf cloud.
This was a high risk day with SPC indicating the threat of damaging tornadoes, but the main risk looked to be due to damaging straight line winds. The forcing was very linear in nature, so it seemed most likely a squall line would form. However, the shear also supported supercells. Indeed, there were a few embedded in the line. Movement of individual storms was to the northeast around 50 to 70 mph, but the line translated east at, perhaps, 40 mph.
This was a fun chase. Ernani and I ran into Gene Rhoden and Alison Storm. The highlight of the chase was stumbling into a tornado-warned storm embedded within an otherwise lame squall line just west of Vici, OK. As soon as the tornado warning was issued, we got out of our cars and looked for the mesocyclone. There it was, immediately to our southwest! There was unmistakeable rotation, but there was no tornado. As we came into Vici, the sirens were blaring and the wet RFD engulfed us in a blinding, white rain at sunset.
Initial view of the storm: plain, dark shelf cloud.
The shelf lost its continuous, solid appearance and developed "bright"
spots. Soon, a tornado warning was issued for our area. We turned around, and the rotation
was immediately to our southwest.
Another view of the mesocyclone (a little closer).