Supercell Tornadoes, Non-Supercell Tornadoes, and

Gustnadoes

Supercell Tornado• Tornado associated with a supercell and

mesocyclone.o Parent storm is persistent, organized, and has an associated

mesocyclone.

• Formation:o Not 100% understood.o Stretching and tilting of vorticityo Rear flank downdraft

• Identify:o Supercell features present

• FFD, flanking line, evidence of rotation in the storm

Supercell Tornado

Flanking Line Rotation

FFD

Non-Supercell Tornado (Landspout)

• By definition this is a tornado.o Not associated with a supercell or mesocyclone, however.

• Associated with a strong updraft.• Difficult to identify with radar

o Storm may be very small or essentially non-existent on radar.• Very little reflectivity

• Formation:o Boundary creates localized vorticity (spin) near the surface.o Strong updraft moves over this vorticity and quickly stretches it.

• Identify:o No supercell features.o Frequently a flat updraft base with a towering cumulus is all that is

visible.

Non-Supercell Tornado

Gustnado• Forms along outflow from thunderstorms

o Eddy along a gust front.o Leading edge of squall line or RFD gust front.

• Does not connect (reach) to the cloud base• Not a tornado• Short lived and ground based (little vertical extent)

Gustnado

Possible gustnado locations

Tornado, Landspout, or Gustnado?