Understanding, Modeling and Predicting Extremes

Weather and climate extremes have profound impacts on both human society and the natural environment. The potential societal payoffs from gains in understanding, predicting and projecting extreme events and their changes are enormous, ranging from improved early warning of extreme events to providing information that is essential for longer-term adaptation decisions (e.g. Findings from the NOAA Science Challenge Workshop, 2011). However, understanding, modeling and predicting extremes remains a great scientific challenge. It involves improved understanding of what causes extremes and their inherent predictability based on suitable datasets (climate reanalysis is often use in such analyses) and improved modeling capabilities with higher resolution and more accurate models. For example, it is recognized that climate processes in the Intra-Americas Sea (IAS) region can affect climate extremes over North America, including tropical cyclone activity and the frequency of droughts and floods (http://www.eol.ucar.edu/projects/iasclip). IAS-related phenomena of relevance to these extremes suggest a potential for predictability on intra-seasonal to decadal time scales. Yet, state-of-the-art global climate models have large mean biases and erroneous variability over the IAS and neighboring regions of North America that limit the capability to use models to fully understand these predictive linkages and improve climate model prediction.

A number of MAPP research areas are relevant to the effort to better understand, model and predict extremes. These include research on ISI climate prediction, climate projections, model improvement, high-resolution climate modeling, and reanalysis.

MAPP has also specifically targeted the modeling of Intra-Americas Sea climate processes associated with extremes over North America (projects run FY12-FY15). These projects include efforts to:

  • Evaluate the modeling of IAS-related processes in state-of-art models
  • Understand the processes underlying the formation of climate model biases
  • Explore how increased resolution or improved physical representations affect IAS biases
  • Evaluate how predictions of climate processes in the IAS/Atlantic Warm Pool region impact predictions in the activity of extremes over North America


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Americans’ health, security and economic wellbeing are tied to climate and weather. Every day, we see communities grappling with environmental challenges due to unusual or extreme events related to climate and weather. In 2017, the United States experienced a record-tying 16 climate- and weather-related disasters where overall costs reached or exceeded $1 billion. Combined, these events claimed 362 lives, and had significant economic effects on the areas impacted, costing more than $306 billion. Businesses, policy leaders, resource managers and citizens are increasingly asking for information to help them address such challenges.