HYSPLIT HREF Dispersion Forecast
EXPERIMENTAL - information may not be current.
Over the past few years, the use of dispersion model ensembles has been an increasingly attractive approach to predict atmospheric transport. The ensembles are generally constructed by combining multiple numerical weather prediction simulations or output from different dispersion models, by introducing variations in a particular model's physics parameterizations, or by different combinations of these variations. In addition, the source term and height distribution can be varied to create dispersion ensembles.
For this application, we create a HYSPLIT ensemble simulation using the 10 meteorological model members from the National Weather Service (NWS) High-Resolution Ensemble Forecast (HREF) that is scheduled for implementation in December 2020. The HYSPLIT model runs are generated by using the Transfer Coefficient Matrix procedure that is updated with the most recent meteorological data at 00, 06, 12 and 18Z.Note that the products may not be current because they are experimental. Output from the HREF itself may not be available and our experimental dispersion runs will occasionally be pre-empted by NCEP operations.
The figures below show each of the simulation ensemble members as well as a series of statistical measures that describe the ensemble properties such as:
Refresh/reload your browser for the most recent images. Click on a thumbnail image to expand. The charts are updated four times per day (~00, 06, 12, 18 UTC).
This web page is under development and is experimental.
Products may change without notice.
Concentrations are relative to the source of 1 unit.
Contour values may vary from day to day and chart to chart.