We were admiring a fine-enough supercell in the western sky when—lo and behold!—I spied out of the left peripheral vision a sight not seen before. Riding along the top of the westward-feeding low-level inflow band was a horseshoe vortex (far middle left), a slowly rotating cloud tube formed from shear-induced stretching of vortex lines. Vorticity already is relatively maximized in these bands, but still, it was a rare treat to see it manifest this way. More often, I have seen horseshoe vortices in blue skies within fields of cumulus, also on days with strong low-level shear. One can see hundreds of supercells (as I have) and still witness something new almost every time, given enough observational attention.
3 S Duke OK (16 May 17) Looking WSW
34.6235, -99.5626Horseshoe Vortex on Supercell Inflow Band
We were admiring a fine-enough supercell in the western sky when—lo and behold!—I spied out of the left peripheral vision a sight not seen before. Riding along the top of the westward-feeding low-level inflow band was a horseshoe vortex (far middle left), a slowly rotating cloud tube formed from shear-induced stretching of vortex lines. Vorticity already is relatively maximized in these bands, but still, it was a rare treat to see it manifest this way. More often, I have seen horseshoe vortices in blue skies within fields of cumulus, also on days with strong low-level shear. One can see hundreds of supercells (as I have) and still witness something new almost every time, given enough observational attention.
3 S Duke OK (16 May 17) Looking WSW
34.6235, -99.5626