Sounding environment · parcel

Microscope drag the ring on the sky

Thunderstorm Lab close

Model

domain

40 km × 16 km · 128 × 64 cells · 312 × 250 m · 5 s steps

dynamics

2-D anelastic · semi-Lagrangian · exact pressure solve (FFT) · frame moves with the 0–6 km mean wind

warm rain

Kessler: saturation adjustment · autoconversion · accretion · evaporation

ice

freezing by temperature · Bergeron growth · riming → graupel · rain freezing · hail growth · melting · deposition / sublimation

latent heat

vaporisation 2.50 MJ/kg · fusion 0.33 · sublimation 2.83 — all fed back to θ

charging

non-inductive graupel–ice collisions in supercooled water · graupel − below −15 °C, + above

E field

3-D point charges of an 8 km-deep slab + image charges under a conducting ground

initiation

130 kV/m × ρ/ρ₀ · halved in heavy precipitation (hydrometeor corona)

leaders

bidirectional · negative end follows −E, positive end +E · ground contact = CG

thunder

every channel segment arrives at d ÷ 343 m/s · 1/d amplitude · far segments low-passed · real-time, not model time

not modelled

rotation (no supercells in 2-D) · corona screening · size spectra · radiation

Controls

click sky

warm bubble +2 K

drag ring

move the microscope probe

space · R · B

pause · reset · bubble at the field

1–5

speed

S · T

sound · tracers

sliders

rebuild the environment and restart

Reading it

dashed lines

0 · −15 · −40 °C in the environment

field

runway + windsock · ground scrolls under the storm-relative frame

altitudes

ft MSL · directions none (2-D)