- 2024 made history
for the warmest winter on record in the US.
And globally, we saw the warmest January
and February ever recorded.
As Earth's average temperatures rise,
data shows us
that winter is the fastest warming season in
most US regions.
So why do we keep having deep freezes
and why do they keep happening in places
like the deep south?
- I'm in Huntsville, Alabama and we got snow
- And January was extremely warm.
15 low temperature records were broken in Kansas,
which is sort of ironic.
And it also makes me wonder how should we prepare
for these complex impacts
as our climate continues to change.
In this episode, we're gonna dive into a new study
that makes the future
of winter in a warming world much clearer.
And to understand winter in the US, we're going to look at one
of the most extreme winter storms in modern history.
The 1993 blizzard that was dubbed The Storm of the Century.
- Here we have ours from March of 1993.
The 13th opens with the line
what most called the worst winter storm in Alabama history
struck Friday afternoon
and lasted until midday Saturday. There's
- No way people can get around, right?
No. If they're at home now, they need to stay there.
If they're not, they need to be trying to get
to really remarkable for any time of the year, even more so
for the last week of winter,
13 inches in Birmingham makes it the biggest snow
storm of all time.
- As global temperatures rise in winter's warm,
we're actually seeing some interesting good news deaths from
cold temperatures are decreasing.
And this makes me wanna understand the storm
of the century more because
although a fact like this may lead one to believe
that massive winter storms like the storm
of the century may be a thing of the past,
recent data says otherwise.
To understand why that is, we're gonna go back to 1993.
- Flowers were blooming, the daffodils were out.
It was the time of spring.
We were up in the seventies on many days,
and everybody was thinking about spring break
and going to the beach.
- So when meteorologists James Spann saw
what looked like an intense winter storm coming late in the
season, he wasn't really sure how to break the news.
- Do you have the guts to go on television
and forecast a catastrophic winter
storm in mid-March?
And quite frankly, I didn't have the guts to do
that five days in advance. I didn't believe it.
- Back in 1993, weather models weren't as good
as they are today,
but this particular system was very hard to dismiss.
The ingredients included a deep area
of low pressure in the Gulf of Mexico
and record cold temperatures dropping down from Siberia. It
- Was forecasted five days ahead of time.
Now, back in 1993, our forecasts weren't very good
after three days,
but this was such a big event
that even the weather forecasting models were
able to pick it up.
- But I was able to see some of the model forecasts
of the storm before it came to shore.
The thing that amazed me about it was the model stayed
pretty consistent on the position
and the strength of the storm.
- With high stakes of an extreme winter storm like this,
James decided to go on air.
- So about three days out we went on television.
And said we could have a major winter storm this weekend,
and I don't think anybody listened.
And I don't blame them. I wouldn't listen either.
This was the middle of March,
- This was the middle of March,
and yet we had a tremendous arctic outbreak of cold weather
all the way down to Alabama.
- The storm hit Alabama the night of Friday,
March 12th, 1993.
- Winter storm 93 blows into Alabama.
- And it was truly the storm of the century.
It blanketed parts of the state with 20 inches of snow,
and Birmingham saw 13 inches.
- You had a true blizzard conditions here in a southern
state, and that's pretty remarkable.
- By Friday morning,
every office from Georgia northward had called every single
county telling them about this storm
and what would happen.
- Oh, good, a snowstorm.
- This was not just an Alabama situation,
this was one
that affected the entire eastern part of the United States.
- It snowed from Mobile all the way up to Maine.
That's a storm.
- This storm was so memorable
that even our experts from previous episodes couldn't help
but share their experiences.
- I remember walking around Central Park,
we had about 13 inches in total.
It was beautiful, it looked great,
but when you try to step on it,
you didn't actually sink into the snow at all.
It was real, literally concrete.
- I was actually living in the Washington DC area. Got about a
foot of snow, but it also turned to rain too.
Everything was almost like concrete when it ended.
- I was very popular in my neighborhood
because I still had my South Dakota snow shovel.
So I was able to help a number of neighbors.
- And our colleague Darren, at PBS even has a shirt
to immortalize the storm.
But what were the consequences in a place like Alabama,
which is so unaccustomed to snow
- Down in town, it was just a nightmare.
- We had upwards of over a half
million people with no power.
We had to move into a hotel 'cause we had no power.
For one week, travel was impossible.
The National Guard had to be called in.
You had women that were going into labor that had to get
to the hospital to deliver their
babies, and they couldn't do that there
- The two
nurses met us halfway.
- Some people needed medication to live.
This was a life death situation.
- And remember this was 1993.
There were no cell phones and most were without power.
So radio became critical.
- The local radio stations became a lifeline.
They stopped playing music,
they stopped their regular format,
and they just took phone calls from people
that had urgent needs.
People were listening and maybe somebody a few blocks away
heard that call and they had that medication
and they could walk it over there.
- Snow is over, but the damage isn't.
- There were over $5.5 billion in damages, equivalent
to 11.6 billion today.
Over 270 people died across 13 states.
Nearly every interstate from Atlanta northeastward closed.
And almost every airport on the East Coast closed at some
point due to the severity of the storm,
representing the most weather related flight cancellations
in US history up until that point.
And from Florida to Maine,
nearly 10 million people and businesses lost electricity.
But again, this was 1993.
Our climate has been warming steadily since then.
So one would think that we're in the clear
for big winter storms, right?
Ironically, a new paper is challenging that assumption,
and we'll get into that.
But first we have to understand
how this super cold outbreak happened.
- The jet stream took on this rollercoaster
shape or configuration.
It went way up to the north over Alaska,
and then came very quickly down on the other side
of the Rockies southward
all the way into the Gulf of Mexico.
So that's about as extreme extent of the jet stream
as you really ever see.
- The jet stream is a high altitude, fast moving air current
that can carry very cold air from the Arctic.
And shortly before the storm of 1993,
the jet stream dipped south over the eastern US.
- The jet stream is generally on the boundary of
that cold air.
And so the jet stream was very far south
and it is along the jet stream that these storms form.
And so because that bulge
of cold air was all the way this far south,
the storm formed on its edge
and then drifted to the northeast
- As the jet stream carried cold arctic air into the south.
It collided with warm, moist air from the Gulf of Mexico.
- We had the coldest air
of the Northern Hemisphere interacting with basically some
of the warmest air in the Northern Hemisphere over a very
short distance, which doesn't happen that often.
- The convergence of these very different air masses was a key
factor in forming the intense low pressure system.
- You have cold air that's falling underneath that warm air
that's going up.
And because of the earth's rotation,
we have something called the Coriolis force.
A storm system starts to form
and spins in a counterclockwise manner.
So this storm was pulling moisture from the south
as it went to the north.
- Like super jet fuel for the storm.
- At this point, the storm was behaving like a hurricane
and Bombogenesis occurred.
And this is when you have a very rapid drop in air pressure,
which suddenly intensifies the storm.
- This is a composite map of
what date was the lowest pressure at the surface recorded.
And this is of all time for all months.
This is the lowest pressure that was observed there as long
as records have been kept.
- Polar air right here coming in,
these lower heights right here will help amplify the storm
that's developing over the Northern Gulf.
- This is intense, almost as intense
as we would see with hurricanes.
In fact, if this system were a hurricane,
it would've been rated category two with the pressure depth
and wind speed that we saw with it
- As the storm traveled north record snow
fell across the region.
- It's bringing in air at sea level,
and that air confronts the mountains is lifted and cooled.
Cooler air cannot hold that moisture that had it sea level.
And so it must fall and it fell as snow
because the air was so cold.
- But this air wasn't just Alaska cold,
it was stratosphere cold, which was due to the polar vortex.
And this is a funnel shaped mass of extremely cold air
that usually lives more than six miles
above the surface of the earth.
And typically it's centered
above the North Pole in a circular configuration.
- That's what we call a strong state.
And the cold air typically stays close to the Arctic region,
- But sometimes it can get disrupted or stretched.
- And during the Superstorm, we had one
of these stretching events,
- When the polar vortex is stretched,
this extremely cold air can break off and move southward.
And that's exactly
what brought record cold air into the southern
and eastern United States.
- And that enabled it to get down
to two degrees in mid-March here, which is still
to this day, the coldest temperature on
record in the month of March.
Next time we have a day like that, I'll be at the cemetery.
- Our climate has been warming steadily since then,
but there's something eerily familiar about the severity
and magnitude of the storm.
- Well, it's all connected.
The superstorm of 93, this extreme cold and the,
and the snow we just had in January for
that two week period, the Texas freeze of 2021,
they all have the same mechanism behind them.
- And that's what's fascinating.
It seems that when this setup occurs in our atmosphere,
it consistently overpowers the warming effects
of climate change.
Judah Cohen published a paper in 2023
that confirms this idea.
We'll link to it in the description.
- The cold extremes aren't trending upward.
- In this study, he looked at the coldest 5%
of each winter from 1960 to 2023,
and he broke them up into three time periods since 1960,
since 1990
and since 2000, he did this to better understand
how winter extremes are changing in four
mid latitude regions.
But today, we're only gonna focus on the Central
Eastern US region.
- We have found that the most extreme
or severe winter weather events in the United States are
associated with these stretched polar vortex events.
So if you go back to 1960,
you clearly see a declining number of these events.
But when you look at that,
the absolute temperature extremity of the cold,
there wasn't a statistically significant difference.
You can identify some warming.
- Since 1960, there has been a decrease in the frequency
and severity of these winter storms.
But something strange happened when Dr. Cohen looked at
how these extreme cold events have been behaving in the last
23 years since the beginning of Arctic amplification.
- Since 2000, you actually have an increase in the frequency
of these extreme cold events.
And there's actually a statistically significant
cooling of the cold extreme.
The cold streams are getting colder. So
- Although we're seeing a lower frequency
of these cold events since 1960
and milder winters overall. Since 2000, in the Central
Eastern US region,
there has actually been an increase in the frequency.
And the coldest 5% of winter events are not warming.
These weather events are actually getting colder.
So as we forge into unprecedented territory
and global temperatures rise, overall,
global patterns become harder to predict
- Relationship between climate change
and extreme winter weather.
It's not monotonic, it's not linear.
Maybe we need to rethink this.
The highs are getting higher,
but the lows are not getting higher.
So it's just the volatility is increasing.
- But I really wanted to know if the storm
of the century could happen again,
- Am I gonna say that Alabama's gonna see 16
inches in the next five years?
I, I, I don't. I can't say that,
but I mean these events do happen all over.
- What we need to be prepared for are the extremes
that are going to continue to occur.
It's the extremes that we are going to be having
to accommodate for the rest of our lives.
- And this seems to be the common theme as we continue
to learn more about our climate systems,
our planet is changing.
And though we might not know just exactly
how our weather will behave in the future,
it's probably wise to adapt and prepare
because as we saw in 1993, our weather has the tendency
to get a little crazy.
Anyway, thanks for watching.
And as always, let us know what you think in the comments
below.