Figure 44. An AWIPS D2D screen showing the new RSAS 15-km North American domain.
Sea-level pressure and 3-hour pressure change analyses are shown for 2200 UTC 10 May 2001.
MADIS
During Fiscal Year 2000, the initial "alpha" version of MADIS was completed and tested by FSL users. The observational
datasets that make up this initial version are shown in Table 1. The observations are acquired by the FSL Central
Facility from a variety of sources, including NOAAPORT, Aeronautical Radio INCorporated (ARINC), and FSL's Demonstration
Division NOAA Profiler Network (NPN) and ground-based Global Positioning System (GPSMet) data hubs. Mesonet data,
decoded and stored with software originally developed for the NWS Local Data Acquisition and Dissemination (LDAD)
system, are provided at over 2,000 stations from local, state, and federal agencies and private firms. Major
contributors to the mesonet datastream are the NOAA Cooperative Institute for Regional Prediction (CIRP) at the
University of Utah, which provides "MesoWest" data from the cooperative mesonets in the western United States,
and the Boulder NWS Forecast Office, which provides mesonet data from the local Denver/Boulder area, and also data
from the Remote Automated Weather System (RAWS) network run by the National Interagency Fire Center (NIFC).
Table 1.
MADIS Datasets
Upper-Air Observations
Radiosonde
Automated Aircraft
NOAA Profiler Network (NPN) Wind Profiler
Surface Observations
Maritime
Meteorological Aviation Reports (METARs)
Surface Aviation Observations (SAOs)
Local Data Acquisition and Dissemination (LDAD) Mesonet
NOAA Profiler Network (NPN) Surface
Global Positioning System (GPS) Surface
The current geographic coverage of the data extends from Alaska into Central America, and plans include extending the
coverage, in some cases, to global domains. MADIS quality control checks were implemented on three levels. Level 1
quality control checks are considered the least sophisticated, level 3 the most sophisticated checks, with level 2
in between.
Level 1 checks include validity checks, which compare the observed values to specified tolerance limits, and position
consistency checks, which compare the current location and time report to previous reports to ensure that a moving
platform's position is consistent with its reported movement. Inconsistent positions are identified as unreal speeds
or unlikely course changes from the last reported position.
Level 2 consists of internal and temporal consistency checks for all observation types, as well as time-height
consistency checks for wind profiler data and hydrostatic, super adiabatic lapse rate, and wind shear checks for
the radiosonde data. In general, temporal consistency checks restrict the temporal rate of change of each
observation to a set of prespecified tolerance limits, and internal consistency checks enforce reasonable
meteorological relationships among observations measured at a single station. For surface data, temporal consistency
checks are performed on all pressure, humidity, temperature, and wind data; for aircraft data, they are applied to
temperature and altitude reports only. A common example of an internal consistency check is the comparison of dewpoint
temperature to temperature: the dewpoint observation must not exceed the temperature observation made at the same
station or both observations are flagged as failing. Internal consistency checks for wind profiler data include a
bird contamination check that inspects and combines profiler measurements of wind direction, velocity variance, and
vertical velocity to detect the presence of bird migration. If birds are determined to be present, the corresponding
wind data are flagged as failing the internal consistency check. The time-height check for profiler data then ensures
consistency in the time and height dimensions of the winds by using pattern recognition techniques to quality control
the current hour's data with past data in a 6-hour sliding window. For radiosonde data, the hydrostatic, superadiabatic
lapse rate, and wind shear checks ensure hydrostatic consistency between vertical layers, and also reasonable vertical
consistency for the temperature and wind data.
MADIS level 3 quality control checks use surrounding observations to check the spatial consistency of the observation
being quality controlled. The only level 3 check supported in the initial version of MADIS is a spatial consistency
check applied to surface observations by the RSAS system running at FSL. Results of the RSAS check are included with
all MADIS surface observations.
The MADIS API, a library of subroutines callable from Fortran, provides access to all of the MADIS observation and
quality control information. In general, the API is very easy to use, and allows each user to specify station and
observation types, as well as quality control choices and domain and time boundaries. With the API, the underlying
format of the datasets remains completely invisible to the user, and many implementation details that arise in data
ingest programs are automatically performed. MADIS API users, for example, can choose to have their wind data
automatically rotated to a specified grid projection, and/or choose to have mandatory and significant levels from
radiosonde data interleaved, sorted by ascending height, and corrected for hydrostatic consistency. Figure 45 shows
the MADIS data available at 1200 UTC on 18 September 2000.
Figure 45. MADIS data available at 1200 UTC 18 September 2000. Circles indicate automated aircraft reports;
crosses indicate surface observations; and letters "X" and "P" indicate radiosonde and wind profiler locations,
respectively.
Projections
MSAS/RSAS
The MSAS and RSAS systems will continue to be improved, including upgrades required to increase grid resolution and
vary domain boundaries. MSAS upgrades on AWIPS will include incorporation of configuration scripts that allow each
NWS Forecast Office to specify the domain and resolution of its local MSAS systems, and also to specify the analysis
grids desired by its forecasters. RSAS upgrades at NCEP will include implementation of a 15-km grid that will cover
the full North American domain.
MADIS
Observations and capabilities will continue to be added to MADIS. The initial version of MADIS described here is
expected to be available to university and government researchers in Fiscal Year 2001. Access will be through a
Web interface that will provide the forms necessary to request real-time and archived data, and allow users to
download the MADIS API, a "READ ME" installation guide, sample programs and data, and a complete User's Guide.
The Web pages will also provide access to an e-mail forum for users to submit questions and obtain answers from
MADIS developers and/or other MADIS users. Access to additional data, including satellite- and radar-based datasets,
is also planned.