Drought Impacts in the Southern Great Plains. Mark Shafer University of Oklahoma Norman, OK

Transcription

1 Drought Impacts in the Southern Great Plains Mark Shafer University of Oklahoma Norman, OK

2 Causes of Drought: Large-Scale, Stationary High Pressure Air rotates clockwise around high pressure steers storms away Air descends = no clouds As long as it sits in place, lots of sunshine, no rain Occurs, to some extent, every summer H

3 Causes of Drought: Feedback from Dry Soils Normally, vegetation and water bodies evaporate water, which cools the air near the ground If there isn t enough water to evaporate, sun s energy heats soil instead

4 Causes of Drought: Ocean Patterns - La Niña Subtropical jet stream brings warm, moist air from central Pacific Ocean El Niño strengthens & shifts the subtropical jet stream = warm, wet La Niña produces a blocking high-pressure that pushes the jet stream northward = dry El Niño La Niña

5 A note about El Niño / La Niña Effects most pronounced in the winter Jet stream is shifted northward in summer; no connection between tropical Pacific and Southern Plains A dry winter and spring can get the dry soil feedback process going in summer (like 2011) Moderate relationship in Oklahoma; stronger in Texas and Southwest In Oklahoma in the Fall, actually reversed relationship El Niño = dry, La Niña =wet Most predictable of the seasonal / inter-annual factors, but only partially explains seasonal rainfall and temperature patterns

6 Phases of ENSO Preference for El Niños Preference for La Niñas Unsettled, but often weak Source: NCA

7 But Wait, There s More North Atlantic Oscillation (NAO) High-frequency oscillation Stronger impact on N. American east coast & Europe Negative tends toward dry southern plains Pacific Decadal Oscillation (PDO) Sloshing between northern and central Pacific, typically year period. May be a major contributor to extended drought patterns (negative phase) Cool phase favors development of La Nina Atlantic Multidecadal Oscillation (MAO) Also long pattern (20-30 years) Warm phase usually dry southern plains More active hurricane seasons as convection shifts eastward

8 When These Align, It Can Be Bad News PDO AMO

9 The Summer of 2011 Started with strong La Niña conditions in Winter Stationary meteorological conditions over a wide regional area Ridge set up over the region and sat all summer Extremes in temperature and precipitation Enlargement of drought area and intensity Feedback from dry soils Widespread drought impacts observed in numerous ecological and economic sectors

10 2011 Southern Plains Drought Impacts At least $12B in crop and livestock losses Lowest cattle inventory in decades Record low water supply Most severe wildfires in Texas, New Mexico History Infrastructure: cracked pavement, foundations, water main breaks 700 a day in Houston at peak million trees killed (Texas Forest Service estimate) In Mexico, 2.5M people in 1,500 communities lacked drinking water

11 Sub-Surface Water Issues Linger Lower Zone Soil Moisture Anomaly NWS River Forecast Center Arkansas-Red Basin

12 Drought varies in time and location, but is always with us

13 Widespread Extreme Drought Every Year

14 Why Plan for Drought? Drought is inevitable Droughts lasting 3-5 years are not that uncommon Pre-drought action shapes choices Increased flexibility and healthy resources minimizes loss Early responses are effective responses The longer you wait, the fewer choices you have Drought creeps up on you Decision points helps limit surprise

15 National Integrated Drought Information System (NIDIS) Integrate observations and data systems Credible and readily accessible information to inform decisions Fill information gaps Develop new tools Drought scenarios Coordinate research and science Intergovernmental and private sector Information dissemination and feedback

16 National Integrated Drought Information System (NIDIS) Enable the Nation to move from a reactive to a more proactive approach to managing drought risks and impacts (NIDIS Act 2006) Drought Early Warning Drought Research Drought.gov Working Groups Upper Colorado RB ACF RB Forecasting Tools & products Engaging Preparedness Communities Southern Plains California NIDIS activities & news Drought.gov Carolinas Coastal Ecosystems Four Corners Missouri RB Pacific Northwest Lower Colorado RB Mid-Atlantic Attribution Drought information uses and improvements Reports and meeting summaries Regional and national drought outlooks Integrated monitoring and forecasting Public awareness and education Interdisciplinary research and applications Seeking new members for the working groups

17 Regional Drought Early Warning Systems

18 Southern Plains Drought Early Warning System Partnership with NOAA, RISA, NDMC, NIDIS, AASC Host forums, workshops, and webinars addressing current regional drought issues 21 webinars and 60 drought briefings, which are available on SCIPP s website and YouTube Discuss impacts and management strategies Promote planning and preparation

19 Drought-based Partnerships and Agreements High-level, formal partnerships Commerce and USDA Sharing of data and information Commerce and Western Governors Association Collaboration on service information needs for climate variability and change Commerce and Interior Coordinate climate-related activities Emergency drought relief bill (for California) Western Governors Association Water resources in the West Also-significant Congressional interest in NIDIS activities

20 Memorandum of Understanding Between the Western Governors' Association and the National Oceanic and Atmospheric Administration Collaboration on Drought, Flooding, and Wildfire Preparedness: Sharing Information and Building Resilience in Planning for Extreme Events June 9, 2014 Colorado Springs, Colorado Objectives and Actions Investigate the interrelationship between drought and wildfire to identify data, information, and analysis needs to inform management strategies. Explore ways to ensure that collection and sharing of crucial drought, flooding, and extreme weather-related data, impact statistics, and information are improved and sustained. Conduct a survey of the existing state and territory Drought Task Forces appointed by Governors to (a) identify data gaps and useful data, information, and analyses and (b) compare and contrast the approaches of the Task Forces so they can learn from one another and better communicate across state boundaries and enhance implementation of drought plans.

21 Informing Decisions - National National Governors Association Meeting February, 2013 National Drought Outlook March 2014 making sure science is on the table when decisions are made (J. Lubchenco) Build on the work of others to create a Coordinated National Soil Moisture Network Congressional hearings

22 Informing Decisions - Regional NIDIS, along with our partners, provides drought information tailored to stakeholder needs Regional drought assessments and outlooks (in-person and webinars) Sector-specific workshops Engaging Preparedness Communities webinars

23 Mark Shafer Associate State Climatologist Oklahoma Climatological Survey Norman, Oklahoma (405) Thank You!