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Snowpack
Wise Owl Did You Know?

Factors Affecting Climate:

  • Distance from the Sea Ocean Currents
  • Direction of Prevailing Winds
  • Topographic Relief Proximity to the Equator
  • The El Niño Phenomenon
  • Human Activity
Water Availability & Drought Outlook: 
Drought Indicators
Planning and managing for drought in Colorado requires diligent monitoring of a variety of dynamic water availability and climate factors including:

  • Monthly Water Supply Report
  • Monthly Climate Report
  • Historical Norms
  • Weather Forecasts
  • Reservoir Levels
  • Stream Flow Data
  • Rain Gauge Sites
  • Snow Course Sites
  • Standardized Precipitation Index (SPI)
  • Surface Water Supply Index (SWSI)
  • Modified Palmer Drought Index
Bringing together a diverse range of skills related to the prediction of water supply availability, weather, climate, and water demand is critical in forecasting water supply availability and the potential for weather related extreme events and mitigating for losses resulting for those events. Numerous tools and resources are available to water resource managers and planners to aid in their efforts to effectively administer their systems to best meet the needs of their users. The Governor’s Water Availability Task Force (WATF), comprised of water supply specialists, emergency management professionals, federal land managers, scientists, and experts in climatology and weather forecasting, refers to and reviews frequently updated information and data from federal, state, and local entities to.    

Where Does the Information/Data Come From?

Division of Water ResourcesColorado Division of Water Resources (DWR)
From the Office of the State Engineer, within Colorado’s Division of Water Resources, comes the Colorado Water Supply Conditions Update, which reports the monthly Surface Water Supply Index (SWSI) for each basin within the State. The SWSI value, developed by the Office of the State Engineer and the USDA Natural Resources Conservation Service (NRCS), is used as an indicator of mountain-based water supply conditions in the major river basins. It is based on snowpack, reservoir storage, and precipitation for the winter period (November through April). During the winter period, snowpack is the primary component in all basins except the South Platte basin where reservoir storage is given the most weight.

Colorado Climate CenterColorado Climate Center
The Colorado Climate Center is part of the Department of Atmospheric Science at Colorado State University in Ft. Collins, Colorado. The Center’s goal is to assist the state of Colorado in monitoring climate over time scales of weeks to years. Climate involves complex interactions between the atmosphere, the oceans, continental glaciers, and the land. Vegetation processes are an important component of the climate system. This service should contribute to a reduction in the state's vulnerability to climate variability and change.
 
National Resources Conservation ServiceNatural Resources Conservation Service (NRCS)
The NRCS provides valuable data, products, and reports on several key water supply and drought indicators, including snowpack, reservoir storage, streamflow, and SWSI. These indicators, when combined, provide a snapshot of current water availability, drought, and flood conditions around the State. The NRCS also disseminates a weekly report, the Snowpack/Drought Monitor Update, which is a concise and informative summary of drought conditions in the western U.S. 
 
U.S. Drought MonitorU.S. Drought Monitor
The U.S. Drought Monitor provides a weekly national drought summary and map. The map uses a drought severity classification system to illustrate drought conditions around the country.


 
National Weather ServiceNational Weather Service (NWS)
NOAA’s National Weather Service is also a key contributor to the information that is evaluated and used to determine the State’s water availability outlook and potential flood and drought conditions. The NWS has three weather forecast offices in Colorado – Denver/Boulder, Grand Junction, and Pueblo. It provides weather, hydrologic, and climate forecasts and warnings for the United States and its territories.

National Oceanic & Atmospheric AdministrationNational Oceanic & Atmospheric Administration (NOAA)
NOAA’s Climate Prediction Center (CPC) offers several tools and resources to forecast drought and climate conditions throughout the U.S.To confer information about drought status on different time scales to those users that need such information, two new experimental products are available which serve as timescale-specific supplements to the U.S. Drought Monitor at a basic level. Both assess conditions based on a blend of several drought indicators, and are depicted relative to the local historic record.

To confer information about drought status on different time scales to those users that need such information, two new experimental products are available which serve as timescale-specific supplements to the U.S. Drought Monitor at a basic level. Both assess conditions based on a blend of several drought indicators, and are depicted relative to the local historic record.
 
The Short-Term Blend approximates drought-related impacts that respond to precipitation (and secondarily other factors) on time scales ranging from a few days to a few months, such as wildfire danger, non-irrigated agriculture, topsoil moisture, range and pasture conditions, and unregulated streamflows.
 
The Long-Term Blend approximates drought-related impacts that respond to precipitation on time scales ranging from several months to a few years, such as reservoir stores, irrigated agriculture, groundwater levels, and well water depth.
 
The U.S. Seasonal Drought Outlook depicts general, large-scale trends based on subjectively derived probabilities guided by numerous indicators, including short- and long-range statistical and dynamical forecasts.
 
The CPC also develops three-month seasonal outlooks, which officially forecast temperature and precipitation for three months at a time. Outlooks can be accessed as far into the future as April, May, June 2007, but skill in these future forecasts may not be as reliable as those forecasts for upcoming months.
 
Through a partnership between NOAA and the Cooperative Institute for Research in Environmental Sciences, at the University of Colorado at Boulder, the Climate Diagnostic Center (CDC) exists and is responsible for the advancement of national capabilities to interpret the causes of observed climate variations, and to apply this knowledge to improve climate models and forecasts and develop new climate products that better serve the needs of the public and decision-makers. CDC develops national capabilities to analyze, interpret, and forecast important climate variations on time scales ranging from a few weeks to centuries. Short-term climate variations of interest include major droughts and floods over the continental U.S. and the global anomalies associated with El Niño-Southern Oscillation (ENSO). These events attract great public interest and often have enormous social and economic consequences.

Among the regional climate forecasts that the CDC publishes are the Colorado (and Interior Southwest) forecasts. In addition to the status and outlook for ENSO (El Niño/Southern Oscillation) and the official CPC forecasts, an experimental forecast guidance for the upcoming three months’ precipitation is posted. Experimental forecast guidance and supplementary information are provided by Klaus Wolter at the NOAA-CIRES Climate Diagnostics Center, Boulder, Colorado. For questions about his forecasts, please contact.
The Intergovernmental Panel on Climate Change defines climate as the state of weather variables (i.e. temperature, precipitation, and wind) with a focus on time scales long than the present, and attention to its role in interactions between land, life, oceans, and atmosphere. The classical time period is 30 years, as defined by the World Meteorological Organization.