Medium Range Severe Weather Risk Assessment for Utility Operations in the Northeastern U.S.A.

Goals:

This project proposes the development of a medium-range severe weather risk assessment tool. The product will be focused on the Northeast (i.e., New England, New York, and much of New Jersey and Pennsylvania) and target the medium range, defined as a forecast lead time of 3 – 10 days. The product will run in real-time, refreshing at least once daily, and predict relative risks of specific hazards (tornado, hail, wind) in the Northeast, as well as their temporal trends. 

Objectives:

The tool will be based on operational forecasts from ensemble-based models, including the Global Ensemble Forecast System (GEFS) and the Ensemble Prediction System (EPS) from the European Center for Medium-range Weather Forecasting (ECMWF). Established weather parameters for each hazard will then be computed. These parameters can include the significant tornado parameter, significant hail parameter, derecho composite, and others. For each parameter, the maximum, median, and/or mean values for the Northeast will be calculated and presented in a color-shaded table form. Such a table will feature each ensemble member as rows, with forecast hour increasing from left to right. Each individual cell will represent the absolute value of the parameter being displayed. An alternate table may be developed to display the relative value of the parameter as compared to climatology. A “consensus” row at the top or bottom of the table will display the mean of the ensemble members. A further step in the project would involve developing a forecast-change-over-time (dProg/dt) table that displays the ensemble mean from the past few days’ worth of model runs as rows, with forecast hour increasing from left to right (see Figure 1 for a simplified sample).