Most supercells spin counterclockwise (cyclonically) in the Northern Hemisphere and move to the right of the average wind direction in their environment. However, some supercells peel away to the left instead. They inhale much of their supply of unstable air on the opposite flank from cyclonic supercells, and rotate the opposite way (clockwise)! Notice, in the mirror image below, how classic this storm would appear if one were looking at it “normally.” This left-mover was one of the strongest ever documented, with 80–90 knots of tight, “gate to gate” rotation detected by two different Doppler radars. Also, note the striking visual resemblance to the multiple tornado-producing Dover OK supercell of 4 Oct 98. [The tail cloud with the clockwise-spinning supercell was obscured from our view by the more dense core.] Though the anticyclonic supercell had little hope of producing a tornado, it provided beauty and wonder aplenty, including a rare double hailbow and deep accumulations of large hail. [With assistance from Steve Hodanish, I’ve published a formal research paper on this fascinating event in the journal Monthly Weather Review. The material in the original SkyPix page formed the foundational seed for that manuscript.] Almost precisely six years later, I would see another anticyclonic supercell in the same county.
1 WSW Aroya CO (15 Jun 2) Looking NW
38.8669, -103.127
