(ESRL/GSD) has established the MADIS (Meteorological Assimilation Data

Ingest System) project to make integrated, quality-controlled datasets

available to the greater meteorological community. The goals of MADIS

are to promote comprehensive data collection and distribution of

operational and experimental observation systems, and to decrease the

cost and time required to move observation systems from research to

operations. Users of the MADIS database have access to a reliable and

easy-to-use database containing real-time and saved real-time datasets

available via http, ftp, or Local Data Manager (LDM).

Observational datasets currently available via MADIS include

radiosonde soundings, automated aircraft reports, NOAA and non-NOAA

wind profilers, non-NOAA experimental microwave radiometer

observations, operational and experimental GOES winds, POES soundings

and radiances, and several types of surface datasets. The latter

includes water vapor observations derived from signals from

geo-positioning satellites (GPS) and a unique national collection of

over 40,000 mesonet stations from local, state, and federal agencies,

and private firms.

Many of the mesonet networks have stations that are located in urban

areas. Examples of these include networks of road weather information

systems operated by state Departments of Transportation, personal

weather stations organized into the Citizen Weather Observing Program

(CWOP), as well as the WeatherBug and UrbaNet networks operated by AWS

Convergence Technologies, Inc. UrbaNet is a surface network designed

to explore the utility of using integrated commercial and government

meteorological data in forecasting within the complex topology of the

urban environment. Another unique network with many urban

observations is the Community Collaborative Rain, Hail & Snow Network

(CoCoRaHS). CoCoRaHS is a network of volunteers who take daily,

manual observations of accumulated precipitation and snow. CoCoRaHS

is organized by Colorado State University, but has been rapidly

expanding in recent years and now has volunteers in most states. In

addition to the surface observations, aircraft ascents and descents

into major airports are organized into soundings of winds,

temperatures, and in some cases, moisture.

All MADIS data files are available in uniform formats with uniform QC

structures within the data files. They are compatible with the NWS

AWIPS systems, and with data assimilation systems such as the Weather

Research and Forecasting (WRF) 3D-variational system. Software

support is provided for all MADIS datasets through the use of an

Application Program Interface (API) that provides users with easy

access to the data and QC information. The API allows each user to

subset the data by specifying station and observation types, as well

as QC choices, and domain and time boundaries. Many of the

implementation details that arise in data ingest programs are

automatically performed, greatly simplifying user access to the

disparate datasets, and effectively integrating the database by

allowing, for example, users to access many different types of surface

observations (e.g. UrbaNet, ASOS, modernized COOP, maritime, and

non-NOAA mesonets) through a single interface. The API can be

downloaded to a user's local computer, or utilized on the MADIS web

server.

First made publicly available in July 2001, MADIS datasets have proven

to be popular within the meteorological community. ESRL/GSD now

supports hundreds of MADIS users, including the majority of NWS

forecast offices, NCDC, NCEP, and many universities and private

companies. Additionally, MADIS supplies non-NOAA data providers with

QC and station monitoring information which have proven useful in

their maintenance activities. NOAA plans to transition MADIS

real-time operations to the NWS and archive operations to the

NESDIS National Climatic Data Center, with ESRL/GSD remaining

the primary research and development organization.

This paper will provide an inventory of MADIS observations available

for urban areas, and will address future plans for expanding the

available datasets. Companion papers by P.A. Miller et al. and

D. Helms et al., will provide additional information on the status of

the MADIS project and on the transition to NOAA operations.

Note - Leon A. Benjamin is also affiliated with Systems Research Group, Inc.