Transcript Document

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Quotes/Images/News Articles From Last Winter
How Cold Was Last Winter
ENSO, Large Scale Patterns (PNA/NAO/AO)
Mean Upper Air Composites From Past Winters
What Indices Can Be Used & Possibly Predict
Warmer or Colder Winters
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December 2013
Backyard Rink Done. Bring on the Cold
Weather!
Might Cry Tears of Joy if There's a Snow
Day Tomorrow.
Snow on ground... Fire in the fireplace…
Good hoops on TV… Thank you, Santa, for
the Early Gift.
January 2014
February 2014
My car handles this Snow about as well as
the Titanic handled the Atlantic Ocean
Best part of the cold!!! predicted a high
of 4 on Thursday. On the bright side
haven't seen a mosquito in months!
March 2014
Global Warming Lecture Cancelled Due to
Unexpected Blizzard
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Coldest Winters in the Twin Cities: 1872-73 to 2013-14
1981-2010 Normal: 18.7 degrees F
(Using Data From xmACIS2. Seasonal Calculations Method –
Average of High/Low Temperature by Days
(December 1st thru February 28th)
1 1874-1875 4.0
2 1886-1887 5.7
3 1935-1936 7.3
4 1872-1873 7.9
5 1903-1904 8.4
6 1916-1917 8.5
7 1882-1883 9.2
8 1978-1979 9.4
9 2013-2014 9.7 (Yes! It was a Cold Winter)
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Due to simplicity, this presentation will use the Minneapolis/St. Paul
International Airport for records, normals and winter trends (Using
Winter
the typical December 1st to February 28th for Climatology).
2013-14
Record Highs
32°
0°
Record Lows
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Average Mean Temperature
Winter Months
Average Mean
Temperature
9.7 F
Coldest In The Last 33 Years
Last Colder Mean
Temperature
Winter of 1978-79 (9.4F)
Average Mean Temperature In Winter
Winter of 2013-14°
Coldest On
Record
4.0 F (1874-75)
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A Reflection of Longevity Vs. Short-Term Cold Spells
What About Extremes…
Lowest Temperatures
That Had Record Lows?
There Were 9 Days In The
Past 33 Years That Were
Colder Than -23 F
Lack Of Extreme Lows In The 2000s
-29F (1983-84),
Only Ranked 43rd
Coldest Winter
-32F (1995-96),
Only Ranked 60th
Coldest Winter
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Consider How Many Days Were Below
+10F, 5F, 0F, -10F, -15, -20F, -25F
During the Last 33 Years? All Recorded Years?
Do You See Any Trends?
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The Top Coldest
Winters Vs. Coldest
Temperatures On
Record
Coldest Winters
1 1874-1875 4.0
2 1886-1887 5.7
3 1935-1936 7.3
4 1872-1873 7.9
5 1903-1904 8.4
6 1916-1917 8.5
7 1882-1883 9.2
8 1978-1979 9.4
9 2013-2014 9.7
Coldest Temp For That Winter
-32
-36
-34
-31
-33
-25
-31
-28
-23
Top Coldest Lows:
1887-88 -41
1879-80 -39
*1886-87 -36
1885-85 -36
1969-70 -34
1935-36 -34
*1885-86 -34
*1903-04 -33
1898-99 -33
Having extreme low temperatures doesn’t necessarily mean a Very Cold Winter And Vice Versa
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Fluctuating Ocean Temperatures along the Equatorial Pacific
- Naturally Occurring Phenomena
- Warm Phase, Cold Phase, Neutral Phase
Effects on the Upper Midwest
- During El Niño Years…
- There is a Higher Probability of a Warmer Winter
- During La Nina Years…
- There is a Higher Probability of a Colder Winter
- During Neutral Years…
- No Significant Probability Either Way.
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1
2
3
5
6
7
8
9
10
2013-2014
1981-1982
2000-2001
1993-1994
1985-1986
2008-2009
1983-1984
1996-1997
1984-1985
2007-2008
9.7
11.7
13.2
13.2
13.5
14.0
14.1
14.4
14.8
15.0
Neutral
Neutral
La Nina
Neutral
Neutral
La Nina
La Nina
Neutral
La Nina
La Nina
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2
3
4
5
6
7
8
9
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2001-2002
2011-2012
1997-1998
1986-1987
1982-1983
1991-1992
1999-2000
2005-2006
2004-2005
1998-1999
26.8
26.2
25.8
25.7
23.9
23.6
23.0
22.8
21.4
21.4
Neutral
La Nina
El Nino
El Nino
El Nino
El Nino
La Nina
La Nina
El Nino
La Nina
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Positive/Negative Phases of the PNA/NAO/AO
Have Larger Effects on Short Term Weather Extremes
Characteristics of +NAO/-NAO
Characteristics of +AO/-AO
Characteristics of +PNA/-PNA
Stronger Jet Stream
Stronger Icelandic Low
Stronger Azores Highs
Warmer Eastern U.S
Less Build Up Cold Air
Cold Air Stays North
Stronger/Less Wavy Jet
Stronger Trade Winds
Below Average 50H in Arctic
Stronger 50H Western U.S.
Colder Air Spills Southward
Northern Plains/Eastern U.S.
Colder/Drier
Colder Air Spills South
Weaker/More Wavy Jet
Weaker Trade Winds
Above Average 50H in Arctic
Stronger Trough Western U.S.
Southwestern Flow
Warmer/Wetter Northern Plains
Weaker Jet Stream
Colder Air Builds Up/Spills South
Colder Eastern U.S.
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Negative AO
Polar Vortex
Positive
PNA
Drops South
As A Result of -AO
Positive
NAO
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Short Term (1 – 3 Weeks)
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PNA… NAO and AO Phases
Long Term (3 – 6 Months)
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El Nino Vs. La Nina Vs. Neutral
http://ssd.wrh.noaa.gov/satable/#
http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml
http://www.eas.slu.edu/CIPS/ANALOG/extended.php
http://hopwrf.info/CFS/
Final Thoughts
The Winter of 2013-14 Was…
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More Cumulative of Cold Temperatures Vs Extremes
A Common Theme For The Coldest Winters in the Past…
• Greater # Of Days Where Overnight Low Temperatures Were Below Zero
The Correlation of the Positive & Negative Phases of the PNA, NAO
& AO Have Much Larger Impacts On Winter Patterns/Trends In The
Upper Midwest In The Short Term (1 - 3 Weeks Out)
For the Upper Midwest to Have A Similar “Cold” Winter of 2013-14
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+PNA, -AO, +NAO Combination (At Least Short Term)
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Scientific Discussions on Climate Change…
- More Extreme Weather Events Are Coming Years
Due To Climate Change
- The Effects of Less Sea Ice in the Arctic is Causing More Severe
Winters in the Northern Plains.
- The Expansion of Antarctica Sea Ice… How Does This Play
In The Climate Change Model
http://www.ncdc.noaa.gov/
http://www.climate.gov/
http://www.globalchange.gov/