A new thrust of hot air into the northern Plains will trigger strong, gustythunderstorms early in the week.Thunderstorms threatening damaging winds and large hail will erupt following aday of heating over much of theWeather HeadlinesMon, 25 Jul 2011 14:18:06 ESTIWS0Mon, 25 Jul 2011 13:37:57 ESTHeat Set to Expand AgainThe second round of heat will not be as harsh, though. Nonetheless, mid andupper 90s are set to return to parts of the Northeast and mid-Atlantic latethis week. People should exercise caution outdoors as the heat slowly creepsback east.Story by AccuWeather.com Meteorologist Andy Mussoline