Heat coming on heels of cool, damp 4th

Chicago's 4th of July weather was a bummer: cool and rainy. The official high of 69 degrees at O'Hare marked the first time since 1997 (66 degrees) that the holiday failed to break 70, and the 0.20 inches of rain was the most since 1.72 inches fell in 1995. The only positive note was that most of the rain ended during the early evening, a few hours before scheduled holiday fireworks. Warmer weather is on the horizon as a persistent dome of hot air that has been baking the central and southern Plains and lower Mississippi Valley with record-breaking heat appears to be making a move toward the area. Triple-digit heat shattered 4th of July temperature records in Texas Saturday, led by a 107-degree high at McAllen. Chicago-area temperatures are expected to surge into the 90s by Thursday and again on Friday for the first time in two weeks. Gulf-level dew points in the 70s will accompany the heat, assuring that recently silent air conditioners will be humming again. The heat will also bring another round of thunderstorms -- adding to area rain totals that are nearly 9 inches above normal for the year.