May 30, 2011: The nation's weather

The hot and stormy weather in the northern Northeast and the northern Mid-Atlantic will come to an end Thursday as the cold front over the area exits into the Atlantic.

Canadian high pressure will build in behind this system with dry and cool northwest winds, leading to a nice break from the heat.

To the south, Invest 93 is expected to reach the Gulf of Mexico early Thursday morning. The system will continue trekking west-southwestward at 15 to 20 mph through Thursday. There is a low chance, 20 percent, of this system becoming a tropical cyclone during the next couple of days as it moves through the Gulf of Mexico.

Elsewhere, in the East, a weak disturbance along the Gulf of Mexico will pull warm moisture into the Southeast, triggering hotter daytime highs and chances of showers and thunderstorms. There is a slight chance of severe thunderstorm development across parts of the Southern Appalachians and adjacent Piedmont.

To the west, a storm system in the Central Rockies will lift northeastward into the Northern Plains. There's a slight risk of severe thunderstorms development Thursday or Thursday night across parts of the Northern Plains. The main threats with these storms will be damaging wind and hail.

Elsewhere, an unseasonably cold trough of low pressure will continue moving through the West with chilly and unsettled weather conditions. Areas of rain showers and high elevation snow are expected to persist in parts of the Pacific Northwest, northern California and the Northern Intermountain West.

Temperatures in the Lower 48 states Wednesday ranged from a morning low of 28 degrees at Bryce Canyon, Utah, to a high of 102 degrees at Florala, Fla.