National Blend of Models Field Demonstrations: A Closer Look

The National Weather Service (NWS) is embarking on a transformational change in the collaborative forecast process and use of its gridded data at its Weather Forecast Offices (WFO) and National Centers. At the forefront of this change is the National Blend of Models (NBM). The NBM will produce a nationally-consistent and skillful suite of calibrated forecast guidance from a blend of both NWS and non-NWS models. As each new iteration of the NBM is produced, a field demonstration at WFOs will ensue a consistent and objective validation process is applied to provide metrics on how the NBM is performing in relation to current forecasting techniques. During the demonstrations, a feedback process will be facilitated that will allow forecaster comments, concerns and suggestions to be collected and considered.

The first evaluation of the new paradigm to use a model blend as a common starting point was provided by the Central Region (CR) Model Blend Proxy Demonstration. This demonstration was conducted from October 4, 2016 through March 31, 2017 and used a regional blend (called a SuperBlend) as a common starting point to provide NWS forecasts as a proxy for the capabilities of the NBM. The demonstration provided key findings regarding (1) the use of a common starting point to free forecasters’ time to provide more Impact-based Decision Support Services, and, (2) the accuracy of the forecasts and consistency of the forecasts across WFO boundaries. The presentation will outline the results from the CR proxy demonstration and discuss the next steps for field demonstrations as they expand to all NWS CONUS regions and include a coordinated collaborative role with the National Center(s).