Page created and maintained by Roger Edwards, Storm Prediction Center
Distrails, short for "dissipation trails," are evaporation paths cut through cloud layers by the heat of a jet airplane's exhaust. Their counterparts, contrails, are more commonly seen cloud streaks left in the wake of planes by cooling of water vapor in their exhaust plumes. Unlike contrails, which require the bitterly cold temperatures of the upper troposphere, distrails can form in one of two ways: in relatively warm, low clouds made of water droplets, or as in this case, from glaciation (icing) of a thin supercooled middle to high level clouds.
Note how each distrail contains a white stripe sandwiched between two dark ones. The glaciation process makes the stripe of cirrus (white), leaving a cloud-free swath on either side.
Like contrails, distrails tend to expand through dispersion as they move away from the track where they were made, becoming many times larger than the plane itself. That was the case here, where the criscrossing trails became big enough to be detected in 1 km resolution visible satellite pictures. The evolution of these trails is seen in this 1.8 MB javascript loop.
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