Probabilistic Forecast Visualization - MDL

The Probabilistic Forecast Visualization effort kicked off in 2017 with the Global Ensemble Forecast System (GEFS) Viewer. Requested by the SSD chiefs, MDL was to prepare visualization capabilities to forecasters to assist in the determination of what is significant in the forecast, the range of possible solutions, and the potential impacts in terms of sensible weather. MDL used, as inspiration, the National Center for Atmospheric Research (NCAR) Ensemble Viewer, the Storm Prediction Center (SPC) High Resolution Ensemble Forecast (HREF) viewer, and ideas from the field to create the initial state of the Ensemble Viewer.

Starting in version 3.0, the National Blend of Models (NBM) was starting to transition to outputting probabilistic data. In preparation for additional probabilistic elements from the NBM, MDL hosted an NRAP partner who extended the initial GEFS effort to view the NBM data in 2018. Throughout 2018 and into 2019, MDL developed and released a few versions of the GEFS and NBM Forecast Viewers with more probabilistic viewing capabilities including meteograms, plume diagrams, wind roses, and QPF accumulation box plots. In addition, the NBM Forecast Viewer designed new capabilities to comb through maps to more quickly get a sense of model certainty of the new probabilistic NBM data. On September 18th, 2019, MDL held a VLab forum to introduce the latest instantiations of the GEFS and NBM Forecast Viewers, and discussed our plans to unify the development efforts into one Probabilistic Forecast Visualization tool that heavily utilizes AWS.

On April 23rd, 2020, the GEFS and NBM Forecast Viewers unified into version 1.0 of the Whole Story Uncertainty & Probabilities Viewer (WSUP). Since then, MDL has made many enhancements to WSUP, including making available more data (multiple versions of NBM, National Digital Forecast Database (NDFD), Unrestricted Mesoscale Analysis (URMA), Probabilistic tropical cyclone storm Surge (P-Surge), and Probabilistic Extra-Tropical Storm Surge (P-ETSS)). Capabilities to dive deeper into data were added, including functionalities like the Comparison tool, that allows users to compare multiple sources at the same time as well as the abilities to create instantaneous bias grids; the Custom Probability tool, that allows users to create a probability of an event occurring based off of the underlying NBM CDF at any value threshold value; and the Component Pie Plot tool, which allows users to compare the component values to a value of their choosing to see how much agreement within the NBM components around the value of interest. The development of WSUP has led to a deeper understanding of how to visualize probabilistic data and what the forecasters need to assist them as the NWS transitions into providing more Probabilistic Impact-based Decision Support Services (IDSS) to our partners. The information gained from WSUP will influence MDLs probabilistic visualization efforts as the focus shifts to a probabilistic forecast data viewer within NWS Connect project and a probabilistic forecast viewer aimed for public release.