… He sends down mountains from the sky with hail inside them, striking with it anyone He wills and averting it from anyone He wills. The brightness of His lightning almost blinds the sight. (Qur'an, 24:43)
The above verse refers to hail and lightning. When the formation of hail and lightning are examined, it can be seen that an important meteorological truth is being indicated in this verse. About the formation of lightning and hail, the book Meteorology Today says that a cloud becomes electrified as hail falls through a region in the cloud of supercooled droplets and ice crystals. Liquid droplets freeze and release latent heat as they collide with a hailstone. This keeps the surface of the hailstone warmer than that of the surrounding ice crystals. An important phenomenon occurs when the hailstone comes in contact with an ice crystal: Electrons flow from the colder object toward the warmer one. In this way, the hailstone becomes negatively charged. This effect also occurs when supercooled droplets come in contact with a hailstone and small pieces of positively charged ice break off. These particles, which are lighter and positively charged, are carried to the upper part of the cloud by currents of air. The hail has a negative charge now, and falls towards the bottom of the cloud, thus the lower part of the cloud becomes negatively charged. These negative charges are then discharged as lightning. It may be concluded from this that hail is the main factor in the formation of lightning.
In the following verse, however, attention is drawn to the link between rain clouds and lightning, and to the order of formation, information that parallels that discovered by science:
Or [their likeness is] that of a storm-cloud in the sky, full of darkness, thunder and lightning. They put their fingers in their ears against the thunderclaps, fearful of death… (Qur'an, 2:19)
Rain clouds are tremendous masses covering 20 to 260 square metres (10 to 100 square miles) and reaching great vertical heights of 9,000 to 12,000 metres (30,000 to 40,000 ft.). Due to these extraordinary dimensions, the lower part of these clouds are dark. It is impossible for the Sun's rays to pass through them, because of the large quantities of water and ice particles they contain. Very little solar energy therefore reaches the Earth through the clouds, which is why the clouds appear dark to someone looking up at them.
The thunder glorifies His praise, as do the angels, out of fear of Him. He discharges the thunderbolts, striking with them anyone He wills. Yet still they argue about Allah when He is inexorable in His power!
As has been discussed, dark layers, followed by the electrically charged sparks known as lightning, and then the loud noise called thunder, form within a rain cloud. Everything modern science has established about clouds, and has to say about the causes of thunder and lightning, is in complete accord with the descriptions in the Qur'an.