Photo Credit: Lt. Zachary West

Texas National Guard soldiers rescue Houston residents from Hurricane Harvey flooding.

Just how bad is the flooding in southeastern Texas? University of Georgia meteorologist and geography professor John Knox is here to explain in a Medium post.

Knox looked at a 5,000 square-mile triangle between Houston, Port Aurthur and Lufkin, TX, that's home to about 7 million people. That region has received approximately 36 inches of rainfall. Calculate it, and that's 3 trillion gallons of water.

To put it in perspective, according to Knox, that's five Lake Laniers worth of water that's fallen on an area the size of Connecticut.

It's so much water that the National Weather Service has had to add new colors to its precipitation maps, UGA atmospheric sciences professor Marshall Shepherd tweeted.

#Harvey in perspective. So much rain has fallen, we've had to update the color charts on our graphics in order to effectively map it. pic.twitter.com/Su7x2K1uuz

— NWS (@NWS) August 28, 2017

Shepherd's Twitter account is another great resource for info on Harvey, and weather and climate in general.

Here's a UGA News Service story on Shepherd. He says the storm could eventually dump 50 inches of rain on the Houston area, calling it a "lingering , unprecedented flooding event."