Non-meteorological constraints that affect convective weather forecasting

In a series of papers in the 1970s and 1980s, Allan Murphy and colleagues discussed the concept of “hedging”, defined as when a forecaster's judgment does not correspond to the actual forecast that was issued. Murphy primarily addressed this phenomenon by exploring the impact of verification systems on the forecasting process. For example, he attributed the mismatch between judgment and actual forecast to factors such as 1) forecasters adjusting their forecasts in an attempt to maximize verification scores, or 2) adjusting forecasts to minimize verification penalties for an inaccurate forecast, i.e., the so-called playing of “verification games”.

Although this topic of “hedging” is discussed less frequently in the literature in recent years, factors other than those purely meteorological still can complicate forecast decision-making in operational forecast centers. And while concerns about verification scores may still contribute to this problem, additional non-meteorological factors can also contribute to differences between forecaster judgment and the actual forecast issued. These include informational loss at times of shift change, background encouragement to maintain forecast continuity so as not to counter the prevailing “forecast philosophy of the day”, the influence of politically-sensitive geographic areas on forecast decision-making, and differences of opinion associated with varying forecast philosophies, both within the office and without. This paper will discuss these topics in light of recent severe weather events to illustrate how non-meteorological issues affect forecasting of convective weather events.