MADIS Meteorological Surface Dataset

Overview

Description

Surface land and maritime observing stations report various meteorological variables that describe the current weather. These variables include basic measurements such as temperature, relative humidity, wind, precipitation, etc., as well as various types of weather occurrences such as hail, fog, and thunder.

The MADIS meteorological surface dataset includes reports from many observing networks run by different "providers". Through the MADIS API, the user can select only a subset of the total by specifying which providers to include or exclude. Most national-scale networks in North America that report surface conditions are included. Over land, this includes all stations that report standard METARs (ASOS, AWOS, non-automated stations) or SAOs (Canadian stations), as well as modernized (i.e., automated) National Weather Service Cooperative Observer (aka NERON) reports and the UrbaNet mesonet. Maritime reports are also available, including the Coastal Marine Automated Network (C-MAN), fixed and drifting buoys, and ship reports. The MADIS meteorological surface dataset also contains a unique collection of thousands of mesonet stations from local, state, and federal agencies, and private firms.

The UrbaNet mesonet and some of the other mesonets are restricted. Click here for details.

• Data Providers and Station Counts

Geographic Coverage

The geographic coverage is densest over North and Central America, plus Hawaii (METAR, maritime, mesonet, SAO - Canada only). Global datasets include maritime and METAR, along with some mesonets: APRSWXNET has a significant number of global observations, and the PCDINPE mesonet is in Brazil.

Data Schedule

Data arrive on a continuous, asynchronous schedule, and the current and previous hour's data are processed every 5 minutes. The data are segmented into hourly files, with the mesonet file for hour HH containing data for HH00 through HH59. In order to get regularly-scheduled hourly reports from the national data sources (METAR, SAO, and maritime) these files contain data starting 15 minutes before the hour and ending 44 minutes after the hour (e.g., the 0000 file covers 2345 - 0044). The most complete data for a given hour is available a little after 2 hours following the file time. The user should also understand that the mesonet data isn't as timely as the national data sources. The lag time of these reports (lag = time available from ESRL/GSD - observation time) ranges from about 8 to 45 minutes, and can sometimes be longer.

Data that arrive after 2 hours following the time of the observation are processed in a "data recovery" mode, where once a day batch processing is performed to reprocess data that are 35 day's, 7 day's old, and 1 day old. These data are available with all communications methods supported by MADIS except for ldm.

Volume

Typical daily volume for all MADIS datasets can be seen here.

Variable Details

• Full Meteorogical Surface
• List of Variables
• Quality Control Processing and Data Structures
• Integrated Mesonet Inventories

Most of the mesonets have all of the basic meteorogical variables (e.g., air temperature, relative humidity and/or dewpoint temperature, wind speed and direction, pressure), but only a subset of mesonets have variables such as soil temperature, etc. Also, different kinds of precipitation measurements are taken by the different mesonets. The following inventories are available to help sort this out.

• Precipitation
• Solar Radiation
• Soil Temperature
• Soil Moisture

Temporal Frequency of Reports

• METAR - most stations report once per hour at a scheduled time, some have a schedule that calls for 3 reports per hour, several more reports can be generated when triggered by certain meteorological conditions
• SAO - all stations report once per hour at a scheduled time, several more reports can be generated when triggered by certain meteorological conditions
• Maritime - most stations report once per hour, some stations may report up to 3 times an hour
• Modernized NWS Cooperative Observer (aka NERON) - The expected reception and observation times are dependent on the type of station. Phase I stations that aren't received over GOES report once per hour, with an observation time of hh:00. Phase I GOES stations send 15-minute observations in a batch once per hour. Phase II GOES stations send 5-minute observations once per hour, and the remaining Phase II stations send 5-minute data every 5 minutes. To determine which stations fall into each category, see the inventory of current data. kept for this network.
• UrbaNet - all stations report every 15 minutes
• Integrated Mesonet - varies by provider, click here for a table of temporal frequency by provider

Related Links

• Federal Meteorological Handbook No. 1 -- Surface Weather Observations and Reports

  This is the definitive United States standard for the Aviation Routine Weather Report/Aviation Selected Special Weather Report (METAR/SPECI) code formats.

• NWS ASOS News and Resources

  The NWS ASOS home page.

• National Data Buoy Center

  The home page of the NWS center responsible for data buoys and C-MAN stations.

• ESRL/GSD Mesonet Network Information

  Links to the various mesonets collected by ESRL/GSD.

• NOAA Integrated Surface Observing System Station Metadata Viewer

  GIS map that can display MADIS mesonet and other NOAA and non-NOAA surface observing station locations and metadata.

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