Arup and Argos Analytics announce expanded WeatherShift™ Toolset

Projected IDF curves describing future rainfall patterns added to climate aware building and urban energy modeling

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San Francisco – Arup, a multidisciplinary engineering and consulting firm with a reputation for delivering innovative and sustainable designs, announced today it has partnered with Argos Analytics, LLC to expand the WeatherShift™ toolset, originally announced on May 12, 2014. The WeatherShift™ toolset takes projections from multiple global climate models and “shifts” present day weather files based on those projections. This can be used in design to test a building or urban environment for performance in a predicted future climate.

The expanded WeatherShift™ toolset now includes the ability to generate projected Rainfall Intensity, Duration, Frequency (IDF) curves that reflect changes in the future climate. IDF curves are a key hydrological engineering tool in widespread use for applications ranging from sizing storm drains to estimating the risk of flooding in a watershed. As the climate continues to warm, evaporation from the oceans is increasing, leading to larger amounts of moisture in the atmosphere. Climate scientists have concluded that this will result in more frequent and more intense extreme precipitation events, which are not accurately reflected in current IDF curves since they are based on historical rainfall data.

The original offering provided an energy modeling capability for buildings and urban environments based on projected EnergyPlus Weather (EPW) files reflecting changes in the future climate, rather than being based solely on historical data. That has since been applied in real world applications in Arizona and the San Francisco Bay Area, as well as in Australia and Brazil.

Though impossible to predict the precise effect of climate change on rainfall in a given location, the Argos Analytics IDFdelta™ tool identifies a range of possible shifts in the IDF curves by analyzing an ensemble of global climate model (GCM) projections using its TRACE™ system. This information enables the generation of projected IDF curves for a given location at a specified point on the distribution of GCM outputs for 2026-2045 and 2081-2100 for both the RCP 4.5 and 8.5 emissions scenarios. The WeatherShift™ toolset’s new IDF capabilities have recently been deployed to inform drainage design parameters in a climate resilience study for Bay Area Rapid Transit’s (BART) facilities in Alameda and Contra Costa Counties in California’s Bay Area. According to A.R. Ann Kosmal AIA, LEED AP BD+C, Convener of the GSA Climate Adaptation and Resiliency Team with the Office of Federal High-Performance Green Buildings and the U.S. General Services Administration: “The investigation and use of climate projections for IDF curves in this project will be valuable for many as the methodology is shared and translated to other locations for climate preparedness and adaptation.” The expanded WeatherShift™ toolset provides both public and private sector entities additional capabilities for preparing the built environment to withstand the impacts resulting from changes in the climate that are well underway and that will continue to become more important. ###


Arup is the creative force at the heart of many of the world’s most prominent projects in the built environment and across industry. Its engineers and consultants deliver innovative projects across the world. Arup opened its first U.S. office 25 years ago, and now employs 1,000 in the Americas. The firm was founded in 1946 with an enduring set of values that fosters a distinctive culture, intellectual independence and collaborative approach. The people at Arup are driven to find a better way to deliver better solutions for their clients. (


Argos Analytics, LLC offers cost effective tools and analysis based on the latest climate science and projections to help public and private sector organizations plan for an uncertain future climate. For more information about Argos, please visit or contact


Jennifer Shelby, CPSM
Rhino PR
+1 508 685 0763

Rebecca Maloney
+1 617 412 6632

Robert Dickinson
Argos Analytics, LLC
+1 650 281 5718