Short Version


  • Narrow Black Stripes along the cyclonic side of bright WV bands and fibres
  • Represent dry (sometimes stratospheric) sinking air
  • Can be used as indication of:
    • Cloud dissipation from above
    • Cyclogenesis
    • Location of jet axis
    • Location of left exit region in a jet streak
  • Also seen in other conceptual models:
    • Rapid Cyclogenesis
    • Wave
    • Jet cloudiness (fibre at jet axis)
    • Front Intensification by Jet Crossing
    • Cold Front
    • Occlusion

The example shows an extended Dark Stripe from Poland towards Spain.