Behind the Forecast: Tracking lightning to predict tornadoes?
Listen to Science Behind the Forecast with Meteorologist Tawana Andrew every Friday on 89.3 WFPL at 7:45 a.m.
LOUISVILLE, Ky. (WAVE) - Could lightning be the key to predicting which thunderstorms produce tornadoes? Some data points to that potential.
As thunderstorms develop, their updrafts and downdrafts (columns of air moving up and down inside the cloud) intensify. Both carry water droplets and ice upward and downward inside the cumulonimbus cloud. The colliding ice and water particles shave electrons off the surface of each other. Eventually, electrical charges build up within the cloud. Usually, there’s a positive charge at the top of the cloud and a negative charge at the bottom. Once a strong enough charge builds up, it will arc through the atmosphere as lightning.
As a storm gets more organized, pulling energy and moisture from the atmosphere, the rate of lightning flashes typically increases. A lot of that lightning may be visible; much of it may remain inside the cloud. When a lightning flash rate significantly surges, that’s called a jump. Sometimes (but not always), the jump may indicate that a thunderstorm may become severe, and a tornado may form.
Mapping the amount of lightning within a storm is incredibly helpful in areas where radar coverage is lacking. It provides meteorologists with another reliable data source. The average lead time for a tornado warning in the United States is between 12 and 14 minutes.
One tool that helps meteorologists track lightning flashing is the Geostationary Lightning Mapper (GLM) on the Geostationary Operational Environmental Satellites - R Series (GOES-R). The GOES satellites are positioned about 22,000 miles above the planet and are in geostationary orbit; this means they are always over the same location, which helps monitor changing weather patterns. GLM tracks not just the location of a lightning strike but its extent and how far it travels.
The use of lightning in severe weather forecasting can help to increase the lead time of severe thunderstorms and tornado warnings, saving lives.
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