The State of the Climate And Extreme Weather. Deke Arndt NOAA s National Climatic Data Center

Transcription

1 The State of the Climate And Extreme Weather Deke Arndt June Feb

2 The world s largest archive of weather and climate data NCDC is located in Asheville, North Carolina A place of active retirement for weather data of many types June Feb

3 Weather is complex The intersection of weather and climate is quite complex The intersection of extreme weather and climate is stunningly complex Science is Conservative 3

4 PART I: Current / Recent State of the Climate PART II: The General Relationship between [Extreme] Weather and Climate June September

5 Most of this presentation comes from four sources: BAMS State of the Climate National Climate Assessment Report Extreme Weather Paper Kunkel et al., (2012). Monitoring and Understanding Trends in Extreme Storms: State of Knowledge, Bulletin of the American Meteorological Society NCDC s Climate Monitoring Branch 5

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7 degrees Fahrenheit 1.2 Global Temperature Decadal Average: Annual Global (Land & Ocean) Temperature Anomaly relative to base period NCDC / NESDIS / NOAA June March September

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11 2012: 55.32F 1998: 54.32F 2006: 54.30F 1934: 54.13F 1999: 53.93F 108 other years 1903: 50.74F 1924: 50.63F 1912: 50.34F 1895: 50.54F 1917: 50.11F

12 Nov June 15, Monthly Climate Webinar

13 2012 year-to-date temperature in bold crimson The other 66 years below it 13

14 Winter Temperature Trends Virginia Maryland 14

15 Spring Temperature Trends Virginia Maryland 15

16 Summer Temperature Trends Virginia Maryland 16

17 Autumn Temperature Trends Virginia Maryland 17

18 Winter Precipitation Trends Virginia Maryland 18

19 Spring Precipitation Trends Virginia Maryland 19

20 Summer Precipitation Trends Virginia Maryland 20

21 Autumn Precipitation Trends Virginia Maryland 21

22 Ayyub, B.M., H.G. Braileanu, and N. Qureshi, 2012: Prediction and Impact of Sea Level Rise on Properties and Infrastructure of Washington, DC. Risk Analysis, Vol. 32, No

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24 Literature Review: Stallone et al. (1976) Weather Climate

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26 How we detect, count and measure extreme events has changed, for each type of event, since the mid-20 th Century. Extreme events are borne from a set of ingredients. Tracking the ingredients is very useful!

27 Instability Several flavors, but generally related to warm, moist air low in the atmosphere, cold, dry air higher in the atmosphere High Instability: powerful updrafts Wind shear Changing of wind speed and/or direction as you go up High wind shear: well-organized, long-lived t-storms and related phenomena Tornadoes need very high wind shear, generally 27

28 Difficult to establish long-term trends because we re so much better at predicting/verifying than we used to be The instability ingredient is likely increasing / will increase The shear ingredient, in the long term, decrease Some long term trends vs. game day issues 28

29 Ingredients Warm water Supportive shear profile 29

30 Still considerable scientific work to be done to determine trends of TC frequency Slightly more confidence that TCs will become more intense (on average) in certain basins Known: Sea level is rising, this makes the impact of a given TC potentially more destructive There will be lots of work to diagnose Sandy in a climate context, but one connection is indisputable: sea level higher now than 50 yrs ago 30

31 Nov June 15, Monthly Climate Webinar

32 Ingredients: Entrenched warm air blocking patterns keep ridges in place, reinforcing the warmth 32

33 Heat waves defined in many different ways, depending on affected population The data are in great shape in the USA The Gist: extreme heat is one of the easy ones. There will be more extreme heat 33

34 Heat waves defined in many different ways, depending on affected population The data are in great shape in the USA The Gist: extreme heat is one of the easy ones. There will be more extreme heat and there already is 34

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36 Ingredients for Extreme Precipitation: Sufficiently moist air Sufficient lift or rising motion 36

37 Another one of the easy ones Rule of thumb (works often, not always) for general precipitation in a changing climate: wet places/seasons/phenomena get wetter; dry places/seasons/phenomena get drier For the most part, the data are in great shape, and support this 37

38 Changes are underway in the U.S. and are projected to grow Projected Change in Precipitation Intensity ( ) Pull over on the side of the road Drizzle Observed Increases in Very Heavy Precipitation (1958 to 2007) June March September

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42 Climate and weather have, in some ways, a teacherstudent, parent-child, coach-athlete relationship Climate affects weather outcomes by changing the frequency and nature of how ingredients come together We are seeing changes in the mean We are seeing changes in certain types of extreme weather 42

43 Deke Arndt