By Rich McKay and Tatiana Bautzer (Reuters) -Portions of Pennsylvania, New York and Mid-Atlantic and Southeast states were still under a National Weather Service watch for damaging wind and tornadoes,

The death toll from tornadoes and violent storms that ravaged the central and southern United States over the weekend has risen to at least 40 people, with dozens more injured, local authorities said.

The weakening but still volatile weather system was moving Monday into the U.S. Southeast and Mid-Atlantic, bringing thunderstorms, hail, damaging winds and the potential for more tornadoes.

Extreme weather warnings remain in place for Florida up through Pennsylvania Sunday before massive storm moves eastward to Atlantic Ocean

America faces another tornado-thunder assault after killer cyclones left more than 30 dead in a weekend of chaos. A massive clean-up across six states will be hampered by another storm whipping up to smash the Midwest.

At least seven tornadoes hit Alabama on Saturday, and that number will likely climb even higher later today. The National Weather Service plans to continue looking at storm damage and has several areas that will be visited by storm survey teams today (Monday).

At least three people were confirmed dead in Alabama after a wave of severe storms spawned tornadoes across the state throughout Saturday evening, causing power outages, downed trees and destroyed structures.

The National Weather Service has survey teams out across Alabama on Sunday surveying damage after many tornadoes are reported to have touched down around the state.