NEAR KARBALA, Iraq (AP) - The ferocious sandstorm that halted the U.S. drive on Baghdad lifted Thursday and coalition warplanes were back in the sky in force, blasting Iraqi light armor that probed American lines as troops resumed their advance 50 miles south of the capital. Troops awoke to bright sunshine after a night when temperatures dipped into the 30s. Small groups of Iraqi armored personnel carriers -- ranging from three to six vehicles -- tested U.S. defenses. When the Iraqis closed within 10 miles, they were blasted by coalition warplanes that again ranged the skies above all of...