Significant tornadoes are possible Saturday during a severe weather outbreak

The likelihood of significant tornadoes increases with widespread severe storms stretching from the central portion of the country to the Great Lakes and the Northeast as we head into the weekend.

"A significant severe weather outbreak is possible for portions of the middle Mississippi Valley on Saturday," the Storm Prediction Center (SPC) said Friday morning.

Unseasonably warm and moist air ahead of an approaching low-pressure system will fuel Friday and Saturday's storms.

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"Confidence is increasing for a potentially potent severe weather setup as ingredients needed for this are appearing to favorably align on Saturday," the SPC said.

Ahead of Saturday's major outbreak, there is a slight risk -- level 2 of 5 -- of storms Friday afternoon for over 6 million people.

This risk area extends over parts of the Midwest from Kansas to Illinois. Large hail is the primary threat, but damaging winds and tornadoes also possible.

The more substantial chance is this weekend.

"The threat ramps up significantly Saturday afternoon into Saturday evening," says CNN meteorologist Dave Hennen.

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Numerous severe storms are likely to develop, with the highest tornado likelihood across the moderate and enhanced areas.

The greatest tornado odds will be focused over northern Illinois.

A moderate risk -- level 4 of 5 -- includes most of northern Illinois.An enhanced risk -- level 3 of 5 -- covers a wider risk area from Missouri and Iowa into Indiana. There is a slight risk -- level 2 of 5 -- includes over 35 million covering much of the Midwest, extending in the Ohio Valley and Southeast.

"Long track, violent tornadoes are possible from the afternoon into the evening," on Saturday, says Hennen.

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In addition to dangerous tornadoes, large to giant hail and damaging winds are possible, said the SPC.

"As the storm intensifies and heads toward the upper Midwest, a wind-driven cold rain is expected to spread across the central Plains on Saturday," the Weather Prediction Center said. "Some of the rain could change over to wet snow Saturday night across the upper Midwest."

The severe threat will likely peak during the afternoon Saturday and persist into the early evening.