Global Warming

1
Global Warming Climate ChangeWhat effect has
it hadon Severe Weather in Illinois?
2
Questions People AskRegarding Global Warming

• Do we get less snow during the winter?

3
Questions People AskRegarding Global Warming

• Do we get less snow during the winter?
• Are there more hurricanes?

4
Questions People AskRegarding Global Warming

• Do we get less snow during the winter?
• Are there more hurricanes?
• Are the hurricanes more intense?

5
Questions People AskRegarding Global Warming

• Do we get less snow during the winter?
• Are there more hurricanes?
• Are the hurricanes more intense?
• Do we get more severe weather?

6
Questions People AskRegarding Global Warming

• Do we get less snow during the winter?
• Are there more hurricanes?
• Are the hurricanes more intense?
• Do we get more severe weather?
• Do we get more tornadoes?

7
Questions People AskRegarding Global Warming

• Do we get less snow during the winter?
• Are there more hurricanes?
• Are the hurricanes more intense?
• Do we get more severe weather?
• Do we get more tornadoes?
• Are the tornadoes more intense?

8
As meteorologists, we need to know these answers!

• Whether we agree with global warming or not!

9
As meteorologists, we need to know these answers!

• Whether we agree with global warming or not!
• It is the HOT TOPIC in our industry.

10
As meteorologists, we need to know these answers!

• Whether we agree with global warming or not!
• It is the HOT TOPIC in our industry.
• Elementary, middle school and high school
  students are doing science projects related to
  the topic.

11
As meteorologists, we need to know these answers!

• Whether we agree with global warming or not!
• It is the HOT TOPIC in our industry.
• Elementary, middle school and high school
  students are doing science projects related to
  the topic.
• Very popular course in colleges and universities,
  degree and non-degree.

12
Schools Teaching Global Warming Climate Change

• Bethel College
• Boston Univ.
• Cal State Univ.
• Columbia Univ.
• Cornell Univ.
• Emporia St Univ.
• Flinders Univ. (Austrl)
• Florida St Univ
• Harvard Univ.

13
Schools Teaching Global Warming Climate Change

• Bethel College
• Boston Univ.
• Cal State Univ.
• Columbia Univ.
• Cornell Univ.
• Emporia St Univ.
• Flinders Univ. (Austrl)
• Florida St Univ
• Harvard Univ.

• Indiana Univ.
• James Cook Univ.
• Johns Hopkins Univ.
• MIT
• Miami Univ of Ohio
• NYU
• Okanaga Univ
• Princeton Univ.

14
More Schools.

• Ohio St. Univ.
• Penn St. Univ.
• Univ of Alaska
• Univ of Arizona
• Univ of Florida
• UCLA
• Univ of Chicago
• Univ of Colo-Boulder

15
More Schools.

• Ohio St. Univ.
• Penn St. Univ.
• Univ of Alaska
• Univ of Arizona
• Univ of Florida
• UCLA
• Univ of Chicago
• Univ of Colo-Boulder

• Univ of Hawaii
• Univ of Maryland
• Univ of Mass
• Univ of Michigan
• Univ of Utah
• Univ of Wisconsin
• Yale University

16
Brain Tease

• WHICH NUMBER SHOULD COME NEXT?
• 144, 121, 100, 81, 64
• 17
• 19
• 36
• 49
• 50

17
Brain Tease

• WHICH NUMBER SHOULD COME NEXT?
• 144, 121, 100, 81, 64
• 49

18
How has global warming affected snowfall in
Illinois
19
How has global warming affected snowfall in
Illinois
20
What about precipitation?Rain and Snow Combined
21
What about precipitation?Rain and Snow Combined
22
Quick Step Back

• What about the United States?
• Has the warming been equally distributed?
• Is it getting warmer moreso across the northern
  plains as opposed to the south?
• Are the winters getting warmer?
• Are the summers getting warmer?
• Is the severe weather season more active?

23
We know that the country is warmer than it used
to be
24
We know that the country is warmer than it used
to be
25
But is it wetter?
26
But is it wetter?
27
Remember Illinois.Not Much Different
28
Where in the US is the warming most concentrated
29
Where in the US is the warming most concentrated
30
Seasonal Variability of Warming..What does it
mean?
31
Seasonal Variability of Warming..What does it
mean?
32
Spring SeasonWhy does the warming slow?
33
Spring SeasonWhy does the warming slow?
34
Why are the summers not following the trend of
winters?
35
Why are the summers not following the trend of
winters?
36
Lets not forget the fall
37
Lets not forget the fall
38
The question Has there been any affect on
severe weather?
39
The question Has there been any affect on
severe weather?

• Data most reliable since 1950.

40
The question Has there been any affect on
severe weather?

• Data most reliable since 1950.
• Data even MORE reliable since late 1980s and the
  implementation of WSR 88-D.

41
The question Has there been any affect on
severe weather?

• Data most reliable since 1950.
• Data even MORE reliable since late 1980s and the
  implementation of WSR 88-D.
• Data EVEN MORE reliable since early 1990s with
  increased awareness due to better spotter network
  and NWS education

42
Brain Tease II

• Sue is both the 50th best and the 50th worst
  student at her school. How many students attend
  her school?
• 50
• 75
• 99
• 100
• 101

43
Brain Tease II

• Sue is both the 50th best and the 50th worst
  student at her school. How many students attend
  her school?
• 99

44
Tornadoes in US since 1950
45
Tornadoes in US since 1985
46
Tornadoes in US since 1995
47
Tornadoes in Illinois since 1950
48
Tornadoes in Illinois since 1985
49
Tornadoes in Illinois since 1995
50
Tornadoes in Chicagoland Since 1950
51
Tornadoes in Chicagoland Since 1985
52
Tornadoes in Chicagoland Since 1995
53
Illinois Annual Temp Since 1950 0.12o /Decade
54
Illinois Winter Temp Since 1950 0.31o /Decade
55
Illinois Spring Temp Since 1950 0.26o /Decade
56
Illinois Summer Temp Since 1950 -0.05o /Decade
57
Let us begin to look more closely at temperatures
in Illinois over the past 25 years when Global
Warming became more apparent.
58
Illinois Annual Temp Since 1980 0.60o /Decade
59
Illinois Winter Temp Since 1980 1.29o /Decade
60
Illinois Spring Temp Since 1980 0.48o /Decade
61
Illinois Summer Temp Since 1980 -0.18o /Decade
62
Tornadoes in the US have been more numerous since
1950.although noticeable dip in the mid to late
1980s
63
Tornadoes in Illinois Since 1950Better
Observations?
64
Tornadoes in Illinois Since 1950F1 to F5
65
Tornadoes in Illinois Since 1950Only F0 Much
better Reporting!
66
Tornadoes in Illinois

• Since 1953 the statewide average is
• 36

67
Tornadoes in Illinois

• Since 1953 the statewide average is
• 36

• Since 1980 the statewide average is
• 44

68
Illinois Spring Temp Since 1980 0.48o /Decade
69
Quick Question

• How much does the influence of a warmer winter
  and slightly warmer spring have on the number of
  weaker tornadoes?

70
Quick Question

• How much does the influence of a warmer winter
  and slightly warmer spring have on the number of
  weaker tornadoes?
• Is it simply better public awareness?
• Is it more advanced remote sensing?

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Top Ten Tornado Years in Illinois

• 2006 124
• 2003 120
• 1974 107
• 1998 99
• 2004 80

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Top Ten Tornado Years in Illinois

• 2006 124
• 2003 120
• 1974 107
• 1998 99
• 2004 80

• 1995 76
• 1999 64
• 1973 63
• 1996 62
• 2000 55

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Top Ten Tornado Years in Illinois

• 2006 124
• 2003 120
• 1974 107
• 1998 99
• 2004 80

• 1995 76
• 1999 64
• 1973 63
• 1996 62
• 2000 55

8 of the top 10 in the last 12 years!
74
Time Series of Tornadoes in Illinois
75
Time Series of Wind Events in Illinois
76
Time Series of Large Hail in Illinois
77
Time Series of SignificantTornado in Illinois
78
Last Brain Tease

• A boy is 4 years old and his sister is three
  times as old as he is. When the boy is 12 years
  old, how old will his sister be?
• 16
• 20
• 24
• 28
• 32

79
Last Brain Tease

• A boy is 4 years old and his sister is three
  times as old as he is. When the boy is 12 years
  old, how old will his sister be?
• 20

80
So what type of severe weather can we expect more
of with Global Warming?
81
So what type of severe weather can we expect more
of with Global Warming?

• Harold Brooks
• Head, Mesoscale Applications Group
• National Severe Storms Laboratory
• We have several problems in answering the
  question
• 1) The datasets of reports haven't been
  collected consistently over the years.

82
So what type of severe weather can we expect more
of with Global Warming?

• Harold Brooks
• Head, Mesoscale Applications Group
• National Severe Storms Laboratory
• We have several problems in answering the
  question
• 1) The datasets of reports haven't been
  collected consistently over the years.
• 2) The sample sizes for small regions are small,
  making trend identification almost impossible
  and, if you aggregate to larger regions, small
  shifts in spatial distribution would be masked

83
So what type of severe weather can we expect more
of with Global Warming?

• Harold Brooks
• Head, Mesoscale Applications Group
• National Severe Storms Laboratory
• We have several problems in answering the
  question
• 1) The datasets of reports haven't been
  collected consistently over the years.
• 2) The sample sizes for small regions are small,
  making trend identification almost impossible
  and, if you aggregate to larger regions, small
  shifts in spatial distribution would be masked
• 3) Interannual variability is large (compare the
  1997-2000 tornado seasons, during a time when
  changes in reporting would have been relatively
  small)

84
So what type of severe weather can we expect more
of with Global Warming?

• Harold Brooks
• Head, Mesoscale Applications Group
• National Severe Storms Laboratory
• All of these things make it hard to detect
  potentially real changes. My guess (hopefully,
  an informed guess) is that changes of 30 in
  real meteorological occurrence on the national
  level over the last 50 years could not be
  detected in the background of the
  reporting/natural variability. 30 would be a
  physically huge change. On smaller spatial
  scales, the fractional change that couldn't be
  attributed would be larger.

85
So what type of severe weather can we expect more
of with Global Warming?

• Harold Brooks
• Head, Mesoscale Applications Group
• National Severe Storms Laboratory
• The take-away message is that we can't tell if
  there have been changes. That doesn't mean that
  there haven't been changes, but detection with
  confidence is much hard than with measurements
  like temperature.

86
So what type of severe weather can we expect more
of with Global Warming?

• Harold Brooks
• Head, Mesoscale Applications Group
• National Severe Storms Laboratory
• This is an area that I'm actively working in, but
  it's probably the hardest problem I've ever tried
  to solve. We're making headway on identifying
  the size of the signal that could be detected and
  in processing the data in creative ways to pull
  out signals, as well as starting to apply climate
  models, but it's not been easy progress.

87
In short What have we found?

• It seems that when we transition from a warm
  winter into a mild spring the nature of severe
  weather events begin earlier in the season
• Even though the number of tornadoes has increased
  over the past 15 years, they have mainly been F0
  type storms
• Strong and violent tornadoes have generally
  remained the same frequency

88
In short What have we found?

• Global warming has NOT HAD ANY significant affect
  on the severity of tornadoes since 1980
• Global warming has NOT HAD ANY significant affect
  on the overall temperature during the summer
  months.
• In fact, the temperature has slightly COOLED in
  the last 25 years.

89
In short What have we found?

• Winters have been warmer and snowfall has been
  less but there is still no overall trend to
  heatwaves and drought.
• More data is needed to see if the recent
  heatwaves and drought although still normal from
  a standpoint of frequency, have become more
  extreme in the short term.
• In other words when it gets dry - is it extreme?
• In other words when it gets hot - is it extreme?

90
What Else?

• Large hail events have not seen any increase or
  decrease since 1980.
• There has been a noticeable increase though in
  high wind events
• These events have begun sooner in the severe
  weather season and have ended later.
• Actual wind speed has not been determined

91
What to do next?

• Check all states between continental divide and
  Appalachians to see how the frequency of
  tornadoes has changed since 1980
• Look for correllation, if any, between large
  scale warming and severe weather frequency.

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Thanx for Listening!