What is interstate-induced clouds and why do they form over Houston?

HOUSTON, Texas (KTRK) -- Amid a rainy and stormy week in early June, an interesting weather phenomenon formed over Southeast Texas.

Southeast Texas is known for having some unique weather features and impacts. Recently, weather satellites were able to pick up a layer of clouds that seemed to form right over local highways and the city of Houston.

Video from June 2, courtesy of NOAA Satellite, shows a layer of cumulus clouds developing and taking the exact shape of Houston's highway system, like I-45, the Beltway, and even the I-10 corridor.

So, what's going on here? While there is no technical term for this phenomenon, the feature is called interstate-induced clouds.

That day, there was a calm, clear weather system overhead, allowing light winds and sunshine to dominate the first part of the day. And with rain the previous day, the sun heated the concrete and asphalt faster than the surrounding ground and waterways. This allowed air right over these highways to rise, cool, and condense quickly, eventually forming clouds right overhead.

The main driver for these interstate-induced clouds is Houston's urban heat island.

An urban heat island is formed when an urban area is warmer than surrounding ones thanks to the number of structures and concrete absorbing and radiating heat. Of course, the rest of the ingredients for clouds to form had to be in place that day as well as a clear view from above to see them.

Overall, Houston's expansive urban heat island influences temperatures and the heat index more than cloud formation. Typically, fair-weather cumulus clouds or light showers form from a sea breeze. However, a recent study from Texas A&M found that cities like Houston, with large urban heat islands, can contribute to the formation of clouds and even showers locally when conditions are right.

It's important to remember this is nothing to be concerned about. Cumulus clouds, whether interstate-induced or not, are normal here in Southeast Texas. As for interstate-induced clouds, it just goes to show that when conditions are right, the weather can do some interesting things in Southeast Texas.