Eventually, the updraft will not be able to support them and the hailstones will fall to the ground - their size and weight dependent on the strength of the storm and how long they stayed aloft. Other times, the droplets may move up and down repeatedly, freezing, melting and growing larger with each trip from top to bottom. Sometimes, when they reach the bottom of the column of air, they will fall from the cloud as rain. As droplets move up, they collide and combine with other droplets and eventually freeze.
It’s quite violent within a thunderstorm - water molecules are banging into one another, rapidly travelling up and down, freezing, melting and freezing again. Hail is ice composed of frozen rain drops that have endured a repetitive freezing/melting process. What is hail and how does it form during thunderstorms? It’s important to remember that lightning can move quickly, so although you are a good distance from where the storm was, you may still be at risk of a lightning strike. The amount of electricity generated can cause a large tree to explode into splinters, while the heat can melt metal and turn sand into glass. Not only is lightning very strong in both its electrical charge (as much as 100 million volts) and heat capacity (more than 35,000 degrees Fahrenheit), but it has also been observed to travel more than 10 miles from its originating cloud. Lightning kills hundreds of people around the world every year, but thousands are killed or injured due to the indirect effects of a storm.
How dangerous is lightning?Įucalyptus tree that was blown apart by a lightning strike in Australia. On occasion, lightning can occur during the daytime, which makes it more difficult to see. If you hear thunder but don’t see the lightning, it may be obscured by a nearby mountain range or clouds. Thunder is the sound made by lightning, so it is not possible to have one without the other. Can thunderstorms occur without lightning? Is there enough heat and moisture to create a storm? If so, will it be a small storm or many large ones? Is there enough for a broad line of thunderstorms to move across an entire state or will the storms last for just a couple of hours and impact only a small area? How much rain is possible? Will there be hail or tornadoes? Will the storms move fast or slow? At what time will they begin and at what time will they end? These questions all factor in when creating a thunderstorm forecast. Meteorologists must also analyze and measure these ingredients. However, the next part gets a bit trickier. If you can find someplace with heat, moisture and a reason for air to move upward you’re on your way to predicting thunderstorms. How do meteorologists forecast thunderstorms?Ī thunderstorm needs two primary ingredients: heat (more specifically, a strong temperature contrast which leads to atmospheric instability) and moisture. With advances in satellite and computer technology and knowing that thunderstorms happen approximately every hour around the world, thunderstorm forecasts are becoming increasingly accurate. How and why thunderstorms form and grow is well understood by meteorologists, but knowing exactly where and when they will form has always been a difficult question to answer. These up and down movements cause friction, building electrical charges that create lightning. These frozen droplets are then pushed downward, where they melt.
These drafts of wind rush air up into the atmosphere, where water vapor and droplets freeze. Looking inside a thunderstorm, one would see a very complex structure living and growing off of contrasts in temperature that drive incredibly powerful updrafts and downdrafts. They’re so big that that just one storm can flood a neighborhood or cause creeks to overflow from rainfall, while the lighting and wind can knock out power for thousands of people. Thunder is the sound made by the electrical discharge of lightning - when air is forced apart by the electricity and then slams back together after the electrical current has passed.Ĭumulonimbus clouds are very large and can have tremendous vertical extent, meaning some can grow to more than 60,000 feet high. Simply put, a thunderstorm is a storm or large cumulonimbus cloud accompanied by thunder and lightning.