Chasing techniques#shear#sounding

Hodograph reading

At a glance

A polar plot of how wind changes with height. The shape tells you everything about what mode of storm you'll get.

Deep dive

A hodograph plots wind vectors from successive heights tip-to-tail on a u-v plot. Key patterns:

Straight-line — splitting storms; left and right movers equal.
Clockwise-curving (veering) 0–1 km — supercell-favoured right movers; high streamwise vorticity.
Anticyclonic curve — left-mover dominance; rare.
Long tail into the 0–6 km — strong deep-layer shear, sustained storm organisation.

The storm motion vector defines the SRH: the area swept between the hodograph curve and the storm motion over the 0–1 km and 0–3 km layers is exactly the helicity.

UK summer hodographs are often straight-line in the deep layer but with useful 0–1 km curvature from surface friction — this is why we get supercells at all.