Presentation on theme: "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."— Presentation transcript:
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
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.
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!
Global Warming Lecture Cancelled Due to Unexpected Blizzard March 2014
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) 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 1 st thru February 28 th )
Due to simplicity, this presentation will use the Minneapolis/St. Paul International Airport for records, normals and winter trends (Using the typical December 1 st to February 28 th for Climatology). Record Highs Record Lows Winter 2013-14 32° 0°
Average Mean Temperature Winter Months Coldest In The Last 33 Years Average Mean Temperature 9.7 F Coldest On Record 4.0 F (1874-75) Average Mean Temperature In Winter Winter of 2013-14° Last Colder Mean Temperature Winter of 1978-79 (9.4F)
There Were 9 Days In The Past 33 Years That Were Colder Than -23 F What About Extremes… Lowest Temperatures That Had Record Lows? A Reflection of Longevity Vs. Short-Term Cold Spells -29F (1983-84), Only Ranked 43 rd Coldest Winter -32F (1995-96), Only Ranked 60 th Coldest Winter Lack Of Extreme Lows In The 2000s
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?
The Top Coldest Winters Vs. Coldest Temperatures On Record Coldest Winters Coldest Temp For That Winter 1 1874-1875 4.0 -32 2 1886-1887 5.7 -36 3 1935-1936 7.3 -34 4 1872-1873 7.9 -31 5 1903-1904 8.4 -33 6 1916-1917 8.5 -25 7 1882-1883 9.2 -31 8 1978-1979 9.4 -28 9 2013-2014 9.7 -23 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 Top Coldest Lows: Having extreme low temperatures doesn’t necessarily mean a Very Cold Winter And Vice Versa
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.
Characteristics of +NAO/-NAO Stronger Jet Stream Stronger Icelandic Low Stronger Azores Highs Warmer Eastern U.S Less Build Up Cold Air Weaker Jet Stream Colder Air Builds Up/Spills South Colder Eastern U.S. Characteristics of +PNA/-PNA Stronger 50H Western U.S. Colder Air Spills Southward Northern Plains/Eastern U.S. Colder/Drier Stronger Trough Western U.S. Southwestern Flow Warmer/Wetter Northern Plains Characteristics of +AO/-AO Cold Air Stays North Stronger/Less Wavy Jet Stronger Trade Winds Below Average 50H in Arctic Colder Air Spills South Weaker/More Wavy Jet Weaker Trade Winds Above Average 50H in Arctic Positive/Negative Phases of the PNA/NAO/AO Have Larger Effects on Short Term Weather Extremes
Negative AO Positive PNA Positive PNA Polar Vortex Drops South As A Result of -AO Polar Vortex Drops South As A Result of -AO Positive NAO Positive NAO
Long Term (3 – 6 Months) El Nino Vs. La Nina Vs. Neutral http://www.eas.slu.edu/CIPS/ANALOG/extended.php http://hopwrf.info/CFS/ http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml Short Term (1 – 3 Weeks) PNA… NAO and AO Phases http://ssd.wrh.noaa.gov/satable/#
Final Thoughts The Winter of 2013-14 Was… 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 +PNA, -AO, +NAO Combination (At Least Short Term)
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/