A terrifying size comparison shows how much rain Hurricane Harvey has produced

Hurricane Harvey has produced 9 trillion gallons of rain since it made landfall on the Texas Gulf Coast on Friday night, and meteorologists forecast an additional 5 to 10 trillion gallons before the storm system subsides.

Numbers that big can be hard to grasp. Fortunately, Matthew Cappucci at the Washington Post featured a graphic in a recent article that puts the volume of rain in terrifying perspective.

By the Post's calculations, if all the water were collected as of noon on August 27, the resulting cube would measure eight cubic miles in volume. In other words, it would be two miles tall with a base of four sides that are also two miles long.

Here's what it would look like in the middle of Houston.

Weather experts are calling Hurricane Harvey "a landmark event for Texas." On Twitter, the National Weather Service declared that it is "unprecedented & all impacts are unknown & beyond anything experienced."

There has been so much rain that the NWS has had to add an additional color to its graphic to accurately capture the volume of water.

Winds reaching 130 miles per hour began whipping through the shores of Texas beginning on Friday night, gradually coming to rest over the southern part of the state as a tropical storm by Monday. Five people have died.

Rain is expected to fall through Tuesday, by which point forecasters have said the storm will have dumped more than 15 to 25 inches of water over the state, and up to 50 inches in certain pockets. The storm is currently inching its way up Texas' eastern shore at roughly 3 mph.