A powerful storm system unleashed violent tornadoes and severe thunderstorms across the South and Midwest on Friday.

Damage assessment is still underway, and it's unclear exactly how many tornadoes have been confirmed so far. But here's a look at the extent of the storms so far.

57 tornado reported in 7 states

There were at least 57 tornado reports across a large area spanning seven states over the past 24 hours, as of Saturday morning, according to meteorologists. The number of tornado reports continued to increase Saturday morning amid an ongoing tornado threat.

The National Weather Service will be conducting storm surveys Saturday to investigate the damage and give a more definitive number of confirmed tornadoes.

Several violent long-track tornadoes caused significant damage, notably in Arkansas, as a confirmed "catastrophic" tornado tore through northwest Little Rock, according to the NWS.

18 fatalities

At least 18 people in six states have been confirmed dead following Friday's powerful storms, per state and local officials:

Nearly 400,000 customers without power

Severe weather was in the forecast Saturday, with damaging winds and an isolated tornado possible for parts of the Northeast.

As of approximately 1:37 p.m. ET, nearly 400,000 customers in five states were experiencing power outages in the U.S. The states with the most outages were:

ABC News' Daniel Amarante contributed to this report.