A feasibility study for probabilistic convection initiation forecasts based on explicit numerical guidance

The annual Spring Forecasting Experiment (SFE) is conducted by the National Severe Storms Laboratory (NSSL) and Storm Prediction Center (SPC) in the National Oceanic and Atmospheric Administration (NOAA) Hazardous Weather Testbed (HWT) during the climatological peak of severe convective weather in the United States. A primary objective of the CI (convection initiation) component of SFE2011 was to examine the potential utility of CAMs (convection-allowing models) with 4-km grid spacing in providing guidance for CI forecasts. The models proved to be quite useful in spite of the fact that many convective and pre-convective processes were coarsely represented with this grid spacing. The models also showed promise in predicting the timing of CI over targeted mesoscale areas, particularly when a probabilistic, ensemble-based approach was considered. Algorithms that identify local CI processes are useful but not sufficient for predicting the disruptive potential of convective storms and larger-scale systems.