What were those towering storms on Monday?

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Pulse storms as seen from space over Alabama around 6 p.m. on Monday. (NOAA)
Leigh Morgan By Leigh Morgan
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on May 13, 2014 at 8:05 AM, updated May 13, 2014 at 9:22 AM

Twitter was peppered last night with images of serious-looking clouds blooming into the atmosphere over parts of Central Alabama.

What were they? Cumulonimbus, frequently seen in the summertime. And the last few days have felt quite summer-like, with rising temperatures and a layer of humid air in place.

Cumulonimbus clouds are the bigger, scarier version of fair-weather cumulus clouds. They are usually much larger than their cauliflower-like peers and reach farther up into the atmosphere. Sometimes you hear them referred to as "towers." They also feature an anvil-like top.

With the right conditions in place, cumulonimbus can morph into supercell storms that are capable of rotating and producing tornadoes.

However, Monday's storms were called pulse storms, which means they pulse up and down in strength and are short-lived. They are common in the summertime.

Also called "single cell storms," pulse storms don't usually produce severe weather, but hail, microbursts, heavy rain and maybe even a weak tornado are possible in the right conditions (but tornadoes from these storms are rare).

Pulse storms come about where there is not much wind shear -- winds blowing from different directions at different heights in the atmosphere.

Storms need an updraft and downdraft to survive. As a pulse storm grows, raindrops will be forced up into the storm until they grow so large that they begin to fall. The drag of air from the falling rain begins to choke off the updraft, cutting off its supply of warm, moist air and shortening its life.

There's a small chance for a few such storms to pop up this afternoon across much of the state.