Severe thunderstorms are firing up in parts of Texas and could trigger high winds, hail and potential tornadoes. More than 100 flights were delayed and dozens more were canceled Thursday at airports in Dallas and Houston. The National Weather Service says the greatest weather risk stretched from just east of Dallas, and between Houston and portions of southern Arkansas and western Louisiana. The risk includes the possibility of tornadoes, wind gusts between 60 and 80 miles per hour and large hail. The National Weather Service issued a tornado watch for several counties in southeast Texas, including the Houston area.