Model Development

Striving to accurately represent the weather from advanced modeling and data assimilation methods is only part of the mission, however; the crux is to not only produce such information in time frames suitable for decision makers, from mission planners to emergency responders, but to couple the meteorology to secondary applications models from which meaningful decision can be made. A full description of the atmosphere – even a perfect one – is useless to sponsors in the absence of tools that can translate the weather information into actions that support their missions. It is the proper coupling of the atmosphere to secondary applications such as transport and dispersion models, air-quality models, damage-prediction models, etc, that perhaps defines the most significant contribution that we can make to our sponsors. The complexity of this undertaking, and the limitations of the tools themselves, requires that one keenly focus on properly quantifying, calibrating, and using the uncertainty information that propagates from the observing platforms, the weather models, and the secondary applications.

RT-FDDA: Real-Time Four-Dimensional Data Assimilation

The RT-FDDA system was developed to provide high-resolution short-term analyses/forecasts (0-12 h). However, recent advances in computing power have allowed for a much longer forecast cycle; up to 36 h at current operational sites given the present grid and model physics configuration. In contrast, the twice-daily MM5 runs were specifically designed to provide long term forecasts (24-48 h).

3-D Variational Data Assimilation

We are currently evaluating 3DVAR techniques at the mesoscale, incorporating a number of non-standard observations that cannot be included in RT-FDDA's observation-nudging scheme, such as satellite radiance, GPS, and radar. 3DVAR is currently being integrated into the RT-FDDA system, yielding a model-based solution which will account for all available observations.

WRF: Weather Research and Forecasting

NCAR is playing a substantial role in the development of this next-generation mesoscale modeling capability. 4DWX developers are currently testing an early version of the WRF, in anticipation of deploying it operationally at various client sites. It is anticipated that the hybrid RT-FDDA and 3DVAR model will be integrated into the WRF framework (anticipated for operational deployment in early 2004).

Global MOD: Global Meteorology on Demand

We are developing the successor to GR-MM5 (Globally Relocatable MM5), a Java-based GUI and visualization tool for controlling MM5-RTFDDA runs on a number of Linux clusters. Global MOD will also have ensemble forecasting modes of operation, and coupled forecast and SCIPUFF capabilities as well.

Coupled Applications

Whereas the model output itself provides valuable information to the forecaster, a great amount of added value is achieved by coupling the analysis and forecast output to secondary models. The 4DWX team is heavily involved in developing such systems, some of which have been deployed for operational use.

  • Noise Assessment and Prediction Capability (NAPS)
    Developed by the Army Research Laboratory (ARL), NAPS is used to predict sound levels generated during the testing of explosives materiel at various U.S. Army test ranges.
  • Second order Closure Integrated Puff (SCIPUFF)
    Developed by Titan System Corporation is part of the Defense Threat Reduction Agency's (DTRA) Hazard Prediction and Assesment Capability (HPAC), SCIPUFF is fed real-time model data in the MEDOC format, and predicts the plume concentration and dosage fields based on user-specified materiel releases.
  • Precision Aerial Delivery Systems (WindPADS)
    Developed by Planning Systems Incorporated (PSI), receives real-time model output converted to the GRIB format, and is used as a planning tool for airdrop Computed Aerial Release Point (CARP) on-board the carrier aircraft while in-flight to the Drop Zone (DZ).