Analyzing and Processing Probabilistic Model Data to Convey Potential Threats to Decision-Makers in the Day 3–7 Period

For the winter season 2013-14, the Baltimore/Washington Weather Forecast Office (WFO) of the National Weather Service (NWS) began experimentally producing and providing a Threat Matrix for the Day 4-7 period for potential winter storm threats. Meteorologists analyze various probabilistic guidance and convey potential impact and forecaster confidence via a 3-by-3 threat matrix. For the winter season 2016-17, this matrix was expanded to cover Day 3, so that the entire pre-watch phase was included.

Feedback from core partners and others regarding this matrix has been widely positive, leading the WFO to pursue expansion of the matrix concept to other threats. Research in summer 2019 (Goldstein et. al) has led to the provisional development of a Day 3-7 Flood Threat Matrix for the Baltimore/Washington WFO area of responsibility. The development and use of these matrices to convey potential threats will be explored and discussed, including examples of prior events.