Since 2005, the Meteorological Development Laboratory (MDL) has been collaborating with the National Center for Atmospheric Research (NCAR) to demonstrate the functionality and capability of NCAR’s AutoNowCaster (ANC) system within National Weather Service operations. Initially, this work focused on the degree to which human forecasters’ interactions with ANC improved the thunderstorm nowcast accuracy above and beyond that provided by ANC alone. The Dallas/Fort Worth Weather Forecast Office (WFO) played a large role in the first five years of this collaboration. Today, the program focuses on assessing ANC’s ability to provide guidance in the form of gridded thunderstorm nowcasts. For that purpose, MDL is running ANC over the Golden Triangle, an area that encompasses Chicago’s, New York City’s, and Atlanta’s Air Traffic Management hubs. This demonstration involves the Chicago WFO, whose forecasters can interact with ANC. The results of this experiment are intended to provide guidance on the utility of ANC in generating convective products that address NextGen requirements. The goal is to develop a concept of operations where ANC feeds the NextGen/4-D weather cube.

ANC runs at the MDL and generates 1-hour forecasts of convective initiation, growth, and decay every five to six minutes. Currently, these forecast products are sent in real time to the Chicago and Melbourne WFOs. Forecasters at these WFOs can interact with ANC using the Advanced Weather Interactive Processing System (AWIPS) Display 2 Dimensions (D2D) interface to create surface boundaries. The forecasters’ inputs are instantly sent to ANC via the AWIPS Local Data Acquisition and Dissemination system. The resulting forecast products--which incorporate the forecasters’ inputs--are then disseminated back to the WFOs. These products are also sent to the Chicago Center Weather Service Unit via web pages.

The ANC system is a suite of automated applications that produces 0-1 hour thunderstorm nowcasting predictor fields derived from observation-based feature detections, numerical weather prediction model output, and human forecaster input. Data ingested by ANC include WSR-88D level 2, satellite, sounding, and surface observations. The software applications in the ANC environment include algorithms for boundary-storm interactions, cumulus cloud detection and growth, boundary-relative shear profile, boundary-relative updraft strength and storm trends and tracks. A fuzzy-logic application is used to combine the weighted outputs from the various analysis algorithms to produce time- and space-specific forecasts of thunderstorm initiation, growth and decay. A more comprehensive and detailed overview of ANC is described in a paper titled NCAR Auto-Nowcast System.