As a national center, NCAR aims to provide atmospheric data and models outputs to the broader community. Our GIS program develops methods and tools that facilitate the use of NCAR models in a GIS. We work with industry and international standards organizations to improve interoperability of common atmospheric data formats, as well as develop tools and applications to increase usability of models and their spatial accuracy. The Climate Change GIS data portal provides GIS-compatible user access to CCSM AR4 global and downscaled U.S. simulations, as well as to the data products that show climate trends and anomalies. To facilitate interdisciplinary research and decision-making on the scales of weather events, the GIS program ensured compatibility of WRF outputs, available in NetCDF format, with the ArcGIS software. A pilot project explored use of web services and web GIS technologies with regard to distribution of WRF and CCSM model outputs. Methods of conversion between sphere-based models and ellipsoid-based data for GIS analysis are being investigated to determine the full potential of the sphere-ellipsoidal shift.  We are investigating the impact this shift may have upon the output positional accuracy for numeric weather models. More information can be found in PROJECTS pages. Visit our DATA page to download available GIS-compatible model outputs.

Extreme Heat Climate Inspector

The System for Integrated Modeling of Metropolitan Extreme heat Risk (SIMMER), a NASA-funded study conducted by NCAR scientists in 2010-2014, focused on extreme heat, human health, and urban vulnerability in present and future climates. The project quantified the importance of explicitly characterizing urban properties to improve urban meteorological simulations, and the role of climate change in the future heat stress across the United States and southern Canada. Climate model simulations from SIMMER suggest high heat stress days and nights in cities across the U.S.

Climate Inspector

Climate Inspector is the newest addition to the NCAR GIS Program's Climate Change Scenarios web portal.  This portal has offered downloadable climate change data in a GIS format to users since 2005.  Climate Inspector is an interactive web application which expands Geographic Information Systems (GIS) mapping and graphing capabilities to visualize possible temperature and precipitation changes throughout the 21st century.

Exploring the use of online GIS technologies

The GIS Program has been exploring the use of online GIS technologies in order to better present results, data, and information to stakeholders.  We have been working with commercial online technology such as ArcGIS Online as well as open source options such as OpenLayers and Leaflet.


ArcGIS Online



The Central American Probabilistic Risk Assessment (CAPRA) project is an ongoing initiative to develop a GIS-based decision-support tool for understanding, visualizing, and communicating disaster risk to decision makers at the local, national, and regional levels.  CAPRA takes a probabilistic approach to risk analysis, using historical occurrences of earthquakes, volcanoes, or hurricanes to create hazard distributions that are combined with local measures of exposure and vulnerability to generate distributions of disaster risk and impacts.

Sphere / Spheroid spatial accuracies

Numerical Weather Models treat the Earth as a perfect sphere, whereas, most geographic data are based upon a spheroidal Earth. When numeric model output is overlaid over the Earth surface characteristics, significant location error can be introduced if the proper conversions are not taken into account. The assumption that all positional coordinates are equivalent introduces positional errors of up to 21 km at mid-latitude locations. Figure 1 illustrates the positional shift when positions from a sphere model are plotted directly onto a spheroid.

Extreme Weather Application

The integration of weather forecast models and socio-economic data is key to better understanding of the weather forecast and its impact upon society. Whether the forecast is looking at a hurricane approaching land or a snow storm over an urban corridor, the public is most interested in how this weather will affect day-to-day activities, and in extreme events, how it will impact human lives, property and livelihoods. The GIS program at NCAR is developing an interactive web mapping portal pilot which will integrate weather forecasts with socio-economic and infrastructure data.

GIS Climate Change Portal

There is a growing demand for climate model projections by a number of user domains which typically use GIS.  This interest has opened the door for interoperability between atmospheric datasets and GIS tools.  One goal of the NCAR GIS Program is to make atmospheric datasets compatible with GIS tools and enable users to gain access, integrate, and manage spatial information, thereby communicating scientific outcomes to the community of GIS users and the stakeholders.   The GIS Program at the National Center for Atmospheric Research (NCAR) has been distributing climate change scenario data in