Skip Navigation Linkwww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
Lightning Safety Program
   
Partners/Links
Contact Us
USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.

Understanding Lightning:
Return Stroke

graphic illustrating text
Figure 1

The return stroke is the very bright visible flash that we see as lightning, caused by the rapid discharge of electricity. Once the step leader makes contact with a streamer, the negative charge that has accumulated along the leader channel flows rapidly to ground. The movement of the charge starts at the point of contact and rapidly works its way upward as charge is drained from the channel (Figure 1.

Although the visible flash is associated with the rapid movement of charge downward, the actual flash propagates upward throughout the channel as the negative charge starts moving toward the ground (Figure 2).

graphic illustrating text
Figure 2

This is similar to cars that have been stopped by an open drawbridge. Once the drawbridge is opened for traffic, cars initially start moving forward toward the bridge but movement across the bridge works its way backward through the line of stopped cars. For a moment after the initial return stroke, the channel remains conductive and can be a favored path for subsequent downward leaders.

Learn about Subsequent Dart Leaders and Return Strokes or Return to Contents page


NOAA, National Weather Service
Office of Climate, Water, and Weather Services
1325 East West Highway
Silver Spring, MD 20910
Questions, Comments?

Disclaimer
Credits
Glossary
Privacy Policy
About Us
Career Opportunities