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Office of Climate, Water, and Weather Services

Coop Modernization

For more than a century, public-spirited citizens all across the country have performed an invaluable service by participating in a network of volunteer observers managed by the federal government. The Cooperative Observer Network is the nation's largest and oldest weather network. The cooperative network was established in 1890 to make meteorological observations and establish and record climate conditions in the United States , primarily for agricultural purposes. Today the network is increasingly used by the National Weather Service (NWS) to support meteorological and hydrological forecasts and warnings and too verify forecasts.

The NWS proposes to modernize its Cooperative Observer Program (COOP). The COOP has evolved into a nationwide weather and climate monitoring network comprised of volunteer citizens and institutions observing and reporting weather elements on a scheduled basis. The data provided by this network is used in many ways: management of water resources, the design and maintenance of buildings, predictions of crop yield, used in economic decision making, flood and drought monitoring and forecasting and the study of climate variability. Modernization of the COOP network will be accomplished in two phases.


The COOP network forms the backbone of temperature and precipitation (including snowfall) observations describing the United States climate. This network of 11,400 volunteer weather observers is located at non-airport locations where people live, work, play, and grow their food. Locations include urban, subuNovember 2, 2007ional, state, and local park settings. This network, and about 1,000 Automated Surface Observing System (ASOS) airport stations, forms the federal government surface weather and climate observing network for the United States . Participants are provided with a set of simple weather instruments and observing instructions by the NWS, which manages the network.

With a few exceptions, the instruments used by cooperative observers have not changed significantly over the past century. Of the currently operating 11,400 COOP stations, about 5,000 make up the "climate" network. The remaining 6,400 cooperative stations support hydrology requirements. Climate stations report 24-hour maximum and minimum temperatures, liquid equivalent of precipitation, snowfall, snow depth, and other special phenomena such as days with thunder, hail, etc. Hydrologic stations report liquid equivalent of precipitation and may also observe river water level heights, 24-hour maximum and minimum temperature, snowfall, snow depth, evaporation, and other parameters.

ASOS airport observations remain the data set used by customers simply because the data are available near real-time on an hourly basis. COOP observations, although eight times more numerous and sited at much more diverse environmental locations, in most cases, are not available for weeks or months after the observations are taken.

ASOS reports in near real-time to support aviation, hydrologic forecasting, weather analysis, and weather prediction. Many are located at or near major metropolitan airports. Most airports have a history of site relocations and instrument changes and/or are located within changing urban environments which has degraded the continuity of the long-term data. In addition, urbanization and the resulting heat island influence (artificial warming) has made airport data complicated to use due to the poor data continuity. The much denser COOP network has been stable as compared to the airport stations.

Need to Modernize the COOP

The sensitivity of our nation's citizenry, property, and economy to damaging weather and climate anomalies continues to grow as does its population and economy. Stories of disastrous weather and climate related impacts at the local, regional, and even national levels are all to frequent. In recent years, floods have been documented to cost the nation hundreds of lives and billions in property damage. Ironically, at the same time, devastating droughts have decimated regional and local economies with tens of billions in property damage, lost wages, and reduced productivity. Snowstorms have paralyzed some states for days, resulting in loss of life, economic productivity, and many other socio-economic hardships. Great swings in temperature-related heating requirements between the mild winter of 1999-2000 and the cold winter of 2000 inflicted hardship on heating customers, affecting the nation's economy.

Such disasters require government assistance through mitigation and corporate risk management. The decision-making process currently relies on an airport surface observation network. To better support efforts to reduce impacts and manage risks, we must modernize our nation's ability to monitor weather and climate with greater resolution and frequency.

Modernization of the COOP network has been formally recommended as a high national priority by the following groups:

  • NWS (1993)
  • National Research Council (1998)
  • American Association of State Climatologists (1999)
  • National Drought Policy Commission (2000)

COOP Modernization

The NWS proposes to modernize the COOP in two phases. Phase 1 focuses on replacement of obsolete equipment and determining optimum network size and distribution and PhasNovember 2, 2007

Phase 1 started in fiscal year 2001 (FY01) with $400,000 to begin the rescue of obsolete equipment. The funding of Phase 1 will continue through FY02 and beyond until Phase 1 is complete. Phase 1 is projected to cost $6.9 million over three years. This effort mitigates potential failures at existing sites, thus avoiding any compromise of the nation's longest and the world's best surface weather record. In Phase 1, NWS plans to replace paper punch mechanisms in the network of 2,700 Fischer & Porter rain gauges. The NWS also plans to replace 5,000 obsolete Maximum-Minimum Temperature Systems. Later phases of the modernization will address the issues of instrument improvement and automated collection and distribution of observations. This phase of the modernization is critical to maintaining NOAA's ability to monitor and analyze climate and weather variability.

Phase 2 is proposed to begin in FY 2003 and will introduce improved sensors and automatic collection and distribution of observational data. Starting in mid-FY 2003, new modular automated equipment will be procured and installed at 325 locations. Deployments will increase to 1,130 annually by FY05 and continue until the complete network is modernized.

COOP modernization will provides the nation with an integrated surface/hydro meteorological monitoring network allowing for unprecedented real-time monitoring of weather and climate conditions.

The COOP modernization will fill gaps in the coverage of the existing COOP network, increase snowfall density and reporting coverage, improve river stage (height) forecast accuracy, provide for better temperature forecasts based on improved sensor distribution, and improve data availability.

The COOP modernization also provides considerable economic benefit. For example, improved temperature forecasts can potentially save the nation hundreds of millions in wasted electric consumption as each one degree Fahrenheit change in temperature equates to about $1 billion in temperature related heating consumption. The COOP modernization projects a 1.5 degree Fahrenheit improvement in local temperature forecasts related to adding 3-hourly temperature forecasts for the additional 8,000 modernized COOP sites. Better risk and water/drought management and economic decisions made by industry, government, and private citizens are other substantial benefits derived from a modernized COOP network.

COOP modernization will be guided by a network spatial density study conducted to identify weather and climate requirements of NOAA, its federal partners, including the aforementioned agencies, and its customers. The study will integrate the network design of the previously mentioned federal surface observing networks to insure stations and observations taken are designed in the most scientific and economical manner.

In summary, the COOP modernization will meet the following requirements:

  • Setting 20 x 20 mile grids (target: 8,000 stations), with increased density in the West/Alaska
  • Making hourly temperature and precipitation data (resolution of 0.01 inch) available in near real- time
  • Obtaining 24-hour snowfall and snow depth daily
  • Transmitting, storing, disseminating and archiving data electronically
  • Measuring soil temperature, moisture, relative humidity, and evaporation in agriculturally sensitive areas to support USDA's requirements.

Additionally, COOP observations will have centralized near real-time Internet data access for observations.

Modernization Benefits

When fully implemented, COOP modernization will provide many benefits including:

Number of gauges showing near real time data: see figure 1 caption for details

Figure 1: Reduction in the WSR-88D radar precipitation error resulting from increasing the number of hourly reporting rain gauges from 10 to 50 (adding 40 COOPs).

Improve NWS's capability to monitor flood, drought and climate variability by increasing surface non-airport reports of daily temperature, all-season liquid precipitation (0.01" resolution) and 24-hour snowfall summary reports by daily receipt of at least one report per element per 20 by 20 mile grid, allowing for a 33 percent improvement in the accuracy and the resolution of the U.S. Drought Monitor and the Seasonal U.S. drought Outlook:

  • Provide NWS forecasters, customers and partners with near real-time standardized, hourly temperature, liquid precipitation (0.01" resolution), and 24-hour daily snowfall observations
  • Provide data with a resolution needed to improve local temperature forecasts by 1.5 degrees Fahrenheit,
  • Improve accuracy of flood forecasts by 23 percent
  • Provide NWS forecasters, customers and partners electronic daily maximum and minimum temperature, liquid precipitation, and 24-hour snowfall for at least two NWS supervised non-airport locations per zone
  • Improve Stage 1 one-hour summer WSR-88D radar rainfall bias corrections by up to 60 percent
  • Increase observation availability for hourly temperature and precipitation and daily 24-hour snowfall and snow depth observations
  • Eliminate daily and monthly temperature biases at all COOP temperature sites, resulting in several degrees (F) improvement in data comparability
  • Eliminate uncertainty in day of occurrence for current 24-hour reported maximum and minimum daily COOP temperatures for all modernized COOP locations
  • Improve COOP precipitation data quality by 20 percent
  • Improve COOP Climatological Data publication (from the National Climatic Data Center ) availability by 50 percent (1 month)
  • Measure soil moisture and temperature, relative humidity, and evaporation measurements at a 60-by-60 mile grid resolution for improved drought monitoring.

Real-time access to hourly COOP network precipitation observations will allow for the first time, real-time corrections for invaluable precipitation estimate biases for weather radars, reducing the WSR-88D precipitation bias error by up to 60%. This will be accomplished by increasing the number of hourly rain gauge reports to support the radar calibration from the current average of 10 per radar (ASOS) to 50 (10 ASOS + 40 COOPs) (Figure 1).

Real-time surface observations will open up broad new opportunities for private sector decision-makers to mitigate adverse impacts and realize economic advantages in developing weather and climate scenarios. The latter will be particularly true for rapidly-expanding applications in the insurance, reinsurance, and weather risk management industries.

Accurate six month forecasts of El Nino and its impacts by the NOAA's Climate Prediction Center combined with the deregulation of energy production has brought significant market forces to the utility industry. During the past two years, NOAA and the weather risk management industry have participated in industry sponsored workshops and have ultimately lead to the establishments of Cooperative Research and Development Agreements. COOP provides the largest and best (and one of the longest) comprehensive national weather and climate observing network in the world and provides vital support to NOAA, NWS, industry, government and customers.

Use of COOP observations has been demonstrated to improve temperature, precipitation, and snowfall forecast accuracy at the local county level. Thus, making COOP observations available nationally in a timely fashion will significantly increase the NWS's ability to accurately detect and forecast weather at the county level and provide customers with a much needed data set representative of where the nation's citizenry live, work, play, and grow their food.

Real-time COOP data is the most spatially detailed surface data providing Weather Forecast Offices with the essential, basic observations required for accurate local forecasts and forecast verification. Better gauges will eliminate 20%-40% of site reporting error rates on the B-91 climatological record forms, published by NCDC for customers. Additionally, users will be able to access the forms in near-real time, unlike present capabilities when up to 4% of the forms are missing and received at least 25 days after the fact.

Academic and NWS studies have shown the COOP data can improve forecast accuracy by 1.5 degrees F for local forecast and also allow for the first time, local forecast verification.

The addition of 8,000 hourly COOP precipitation reports in near real time is expected to improve the NWS's accuracy of river stage forecasts significantly (figure 3).


The COOP network has been very successful in meeting its original 1890 agriculturally oriented mission. However, many other uses of the data have since emerged. These applications include climate change and variability, water management, drought assessment, environmental impact assessment, litigation, engineering and architectural design, energy consumption studies/models, crop yield forecasts, and NWS local forecasts, warnings, and verification.

Recently, high value applications of the data for use in energy industry (i.e., load forecasting) ($500 B) and the expanding Weather Risk Management Industry ($10 B) have been discussed. Many of these applications require both historical climate data and timely access to current observations.

In summary, there is an exploding demand for higher density, real-time surface data by weather-sensitive industries and private and public weather services. The demand far exceeds the NWS's current capabilities. The COOP network needs to be modernized.


NOAA, National Weather Service
Office of Climate, Water, and Weather Services
1325 East West Highway
Silver Spring, MD 20910
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Last Updated: June 21, 2013

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