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Castle A. Williams
and
Gina M. Eosco

ABSTRACT

Although both research and practice contend that message consistency is a critical component of effective risk communication, neither provide systematic evidence demonstrating if, when, and where consistency matters. For this reason, meteorologists view message consistency as both a relevant research and operational concern. To address these concerns, members of the weather enterprise organized conference sessions, panels, webinars, and workshops to achieve message consistency, but were unable to make progress without a definition. Fortunately, research scholars in the fields of psychology and communication studies offer important theoretical insights for defining message consistency. As such, this paper takes an important first step by combining the needs of operational meteorologists with insights from social science research to offer a definition of message consistency for the weather enterprise. While it is logical to present both a definition and a recommendation on how to achieve message consistency, the systematic review revealed various research limitations and practical constraints that call into question the feasibility of achieving it. To further bridge research and practice, this paper recommends that researchers and practitioners collaboratively develop a message consistency evaluation process for the weather enterprise. A persistent community effort will shed light on when, where, and under which circumstances consistency is necessary, and more importantly, move us one step closer toward achieving a more consistent message within the weather enterprise.

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Paul W. Miller
,
Alan W. Black
,
Castle A. Williams
, and
John A. Knox

Abstract

Human wind reports are a vital supplement to the relatively sparse network of automated weather stations in the United States, especially for localized convective winds. In this study, human wind estimates recorded in Storm Data between 1996 and 2013 were compared with instrumentally observed wind speeds from the Global Historical Climatology Network (GHCN). Nonconvective wind events in areas of flat terrain within the continental United States served as the basis for this analysis because of the relative spatial homogeneity of wind fields in these meteorological and geographic settings. The distribution of 6801 GHCN-measured gust factors (GF), defined here as the ratio of the daily maximum gust to the daily average wind, provided the reference upon which human gust reports were judged. GFs were also calculated for each human estimate by dividing the estimated gust by the GHCN average wind speed on that day. Human-reported GFs were disproportionately located in the upper tail of the observed GF distribution, suggesting that humans demonstrate a tendency to report statistically improbable wind gusts. As a general rule of thumb, humans overestimated nonconvective wind GFs by approximately one-third.

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Paul W. Miller
,
Alan W. Black
,
Castle A. Williams
, and
John A. Knox

Abstract

Nonconvective high winds are a deceptively hazardous meteorological phenomenon. Though the National Weather Service (NWS) possesses an array of products designed to alert the public to nonconvective wind potential, documentation justifying the choice of issuance thresholds is scarce. Measured wind speeds from the Global Historical Climatology Network (GHCN)-Daily dataset associated with human-reported nonconvective wind events from Storm Data are examined in order to assess the suitability of the current gust criteria for the NWS wind advisory and high wind warning. Nearly 92% (45%) of the nonconvective wind events considered from Storm Data were accompanied by peak gusts beneath the high wind warning (wind advisory) threshold of 58 mi h−1 (25.9 m s−1) [46 mi h−1 (20.6 m s−1)], and greater than 74% (28%) of all fatal and injury-causing events were associated with peak gusts below these same product gust criteria. NWS wind products were disproportionately issued in areas of complex terrain where wind climatologies include a greater frequency of high wind warning threshold-level gusts, irrespective of observed impacts. For many areas of the eastern United States, a 58 mi h−1 (25.9 m s−1) gust of convective, tropical, or nonconvective origin falls within the top 0.5% of all observed daily maximum wind gusts, nearly eliminating the possibility of a nonconvective gust meeting the issuance criterion.

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Alan E. Stewart
,
Castle A. Williams
,
Minh D. Phan
,
Alexandra L. Horst
,
Evan D. Knox
, and
John A. Knox

Abstract

Prior surveys of the public indicated that a variety of meanings and interpretations exist about the probability of precipitation (PoP). Does the same variety of meanings for the PoP exist among members of the professional atmospheric science community? What do members of the professional community think that the public should know to understand the PoP more fully? These questions were examined in a survey of 188 meteorologists and broadcasters. Meteorologists were observed to express a variety of different definitions of the PoP and also indicated a high degree of confidence in the accuracy of their definitions. Differences in the definitions stemmed from the way the PoP was derived from model output statistics, parsing of a 12-h PoP over shorter time frames, and generalizing from a point PoP to a wider coverage warning area. In this regard 43% of the online survey respondents believed that there was no or very little consistency in the definition of PoP; only 8% believed that the PoP definition has been used in a consistent manner. The respondents believed that the PoP was limited in its value to the general public because, on average, those surveyed believed that only about 22% of the population had an accurate conception of the PoP. These results imply that the atmospheric science community should work to achieve a wider consensus about the meaning of the PoP. Further, until meteorologists develop a consistent conception of the PoP and disseminate it, the public’s understanding of PoP-based forecasts may remain fuzzy.

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