Forecasting technique: An operational ingredients-based methodology for forecasting midlatitude winter season precipitation

Abstract

An ingredients-based methodology (IM) for the operational analysis and prediction of midlatitude winter season precipitation is developed. Diagnostics for five fundamental physical ingredients involved in the production of precipitation-forcing for ascent, moisture, instability, precipitation efficiency, and temperature-are incorporated into the IM. The forcing ingredient is combined with the instability ingredient to form a new parameter, PVQ, that serves as an indicator of heavy precipitation potential by identifying regions where these two ingredients coexist. The diagnostics and PVQ are incorporated into ingredients maps that facilitate a systematic approach to forecasting the duration, intensity, and type of winter precipitation.