HOUSTON --You may have noticed there is a thick haze of smoke over parts of the city Thursday evening. The Woodlands Fire Department told us that the U.S. Forest Service is conducting a series of controlled burns on the north end of Lake Conroe in Walker county on approximately 1,000 acres. After receiving several calls, we sent SkyEye HD to check it out. We found thick smoke in the Woodlands and Grogans Mill area. There were also reports of smoke in Spring. ABC13 Chief Meteorologist Tim Heller said the smoke is moving from the north/northwest to south/southeast direction. So far the Houston Airport System says no flights are affected. No word how long the burns are expected to last. We'll keep you posted on abc13.com and on Eyewitness News. If you caught photos or video of the hazy skies overhead, you can upload them at iWitness.abc13.com or email them to email@example.com.