Downburst - INSIGHT STRIKE FINDER Pilot's Manual

STRIKE FINDER
This is often oversimplified as positive charges at the upper reaches and
negative at the base, (see Figure 37).
Lightning takes place when the positive and negative charge has a
voltage difference of about 300,000 volts per foot. Lightning strikes at the
speed of light. It may contain up to 200,000 amps of current. With instant
air temperature peaks of 50,000˚F along the discharge channel, it is hotter
than the sun's surface temperature. The ambient air is exploded into a
sonic boom called thunder.
There are three lightning routes: cloud to ground, between the clouds and
within the cloud. Most lightning strikes take place within the clouds or
between the clouds where aircraft are defenseless targets.
Figure 37. Charge Separation

Downburst

Downburst refers to air coming down from a shower or a thunderstorm,
hitting the ground, and spreading out. The violent downburst outflow is
typically contained within a 3 mile diameter, although velocities beneath
thunderstorms have been measured to travel 18 miles in advance of the
thunderstorm itself.
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DIGITAL WEATHER AVOIDANCE
PILOT'S GUIDE