>> Today's storms were another reminder of extreme summer weather that's becoming more common in the Midwest.

But winter is coming as it always is in Chicago.

And meteorologists are predicting this year's El Nino weather pattern to be one of the strongest in decades.

Warm waters in the Pacific Ocean could affect whether all around the globe from now until spring here to break down what it means and what folks might want to prepare for in Chicago is Scott Collis and atmospheric scientist at Argonne National Laboratory.

Welcome back.

Good to see you in person.

Good evening decided to see you So before we talk about on let's talk a little bit about today, latest round of severe storms this summer, what happened?

So the National Weather Service as of now has confirmed 2 tornadoes, sofa.

>> One will county, one in Cook County and I need to stress.

Cruise is still out right now.

not down into Indiana.

It in done done, done damage surveys down there.

>> What you said was very apt.

The storm as it came through the western suburbs at the Cannes, what we call organized became basically a wall of storms that's tied to spin-up tornadoes along the front as it moved through Chicago.

It just became this wall of wind that, as you said, was equivalent to EF 0 tornado minus rotation.

Plus the massive area as it went through.

this morning we have our own tornado warning here in the studio actually in this area.

Do we know what we know about where that >> confirmed?

Tornado in Cook County was?

I don't know the exact location The weather service will release the tracks when they finish base out.

They really just release those counties and locations right now.

The way it works is the public give damage reports.

We look at where we think those tornadoes touched down.

According to weather and crews dispatched to those areas and it is the responsibility of the National Weather Service to determine whether 20 to happen on and they busy decide what happen NATO's in Illinois this year.

So >> again, this is breaking news.

So the last time I looked into this, what was on the 27th after the last tornado outbreak?

We're at 191 tornadoes.

When we look at the total number tornadoes in a state, the record number of 10 has we came 3rd behind Texas and Texas.

what that means is had more tornadoes this season any other tornado season in a place like Oklahoma, Alabama, for instance, it's been it's been crazy.

Was that tell you tornadoes are really hard to attribute what it's told All the ingredients for a tornado have existed over the spirit is been wet.

It is been hot and we have had just the right path.

Tons of winds above to make those storms spin-up.

Now the thing about this kind of weather, the site, we like to research a dog on National Park tree is it's reinforcing when it rains a lot.

The soils get wet.

It becomes very conducive to new storms and so on so forth.

It goes around.

Okay.

So now it's only knew.

Remind us what it is.

It's another one.

This self-reinforcing Patton's, the loads, the dice 4 especially for our wind.

It's a really a win to time phenomenon what it is.

There's a time of war to off the deck with total coast of South America right along the equator with the trade winds actually meet back gets warmer than about half a degree.

And they'll Nina forms with full costing forget about 2.5 degrees.

What's called a very strong El Nino.

What that means is there is big change in temperatures from the equate us to the mid polls.

Storm systems like to run along those changes in temperatures with the jet stream likes to sit.

So when that El Nino is strong, storms shift to asked South, they tend to miss Chicago.

So we will have a Well, that's right.

The dice will be loaded for a warm and dry out when to the normal.

You mentioned a very strong El Nino.

Some folks have thrown around the term super El Nino.

>> Why so much stronger super this year.

they called the 2015 16.

0, no.

The Godzilla, they'll you know, I prefer that one super El Nino is known officially to a trickle time.

But we'll go with It happens because there's a set of winds cold, the trade winds and when they slap and when they get week, it allows warmer water to form this list.

Clouds this list, storms pushing of the back from those winds.

Unlike the winds that we feel that, you know, we're on out about ways ISIS actually run from the west towards high from the east, towards the west.

So they push that warm water off towards Asia and Australia.

But now because those winds of slack and that warm Tang developed how a passel ninos affected the Chicago area.

the 2015, 16 El Nino was very typical for Chicago It was we actually got a 5th of precipitation that but feel as rain, sleet and freezing rain during that season rather than snow.

We had about normal precipitation that you remember these load the dice.

We had a much warmer when to that.

Okay.

What a globally.

Okay.

Globally the Patton is receiving even across United States for America.

It's quite different.

For instance, southwest, Colorado, Arizona, is likely to see more snow because those storm tracks will go closer to those mountain ranges and cause those mountain ranges.

Nice.

A high.

They really don't care about it.

Warming up so much.

It is.

And this is from where I mean, about X?

And for reading from Australia, it's a potent for droughts and wildfires that down in Australia.

So it really does.

Disrupt global Patton's.

The reason why we use things like you'll notice to do the seasonal prediction is that the oceans changed slow than the atmosphere.

So again, they can give us an idea of how the dice have been loaded.

So we have El Nino forecast over the coming months from NOAA, the National Oceanic Atmospheric Administration.

>> Can you walk us through what this graph is telling us, Scott?

So this is showing us by by season the chances of a very strong, strong weak El Nino.

If you look at that they which is over, I went to which we can see from just by looking at that's where would most like to see, you know, when there, 0% chance we will not have Nina and there's an 80% chance.

It'll be a very strong like the 15, 16 El Nina.

How do scientists forecast?

Yeah.

very important time to do a full castilian.

You know, there people involved in this.

They use a mix between statistical relationships between those sea surface temperatures and what normally happens.

You basically look during an El Nino What did I normally see in Chicago, Boston and Danville.

We also use numerical models.

Numerical simulations where we actually simulate the ocean currents and things like that.

It's still state of running one of these where the simulations where we actually can join the ocean and atmosphere together and have them talk to each other out.

There is more energy moved in the first 10 meters of the ocean, the entire atmosphere and and their their buoys in the ocean.

That's correct.

help do all this.

Is that how tight and a right this is gold standard for collecting this information because the satellites we normally use to just look at ocean temperatures.

They come penetrate and at the center.

So it might be really warm at the surface, but really called underneath this tell trying always told us that that warm time it's about 150 meters date so that warm water is not going anywhere anytime All right.

There's a meteorology