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Climatological Estimates of Daily Local Nontornadic Severe Thunderstorm Probability For The United States


The probability of nontornadic severe weather event reports near any location in the United States for any day of the year has been estimated. Gaussian smoothers in space and time have been applied to the observed record of severe thunderstorm occurrence from 1980 to 1994 to produce daily maps and annual cycles at any point. Many aspects of this climatology have been identified in previous work, but the method allows for the consideration of the record in several new ways. A review of the raw data, broken down in various ways, reveals that numerous non meteorological artifacts are present in the raw data. These are predominantly associated with the marginal nontornadic severe thunderstorm events, including an enormous growth in the number of severe weather reports since the mid-1950s. Much of this growth may be associated with a drive to improve warning verification scores. The smoothed spatial and temporal distributions of the probability of nontornadic severe thunderstorm events are presented in several ways. The distribution of significant nontornadic severe thunderstorm reports (wind speeds >= 65 kt and/or hailstone diameters >= 2 in.) is consistent with the hypothesis that supercells are responsible for the majority of such reports.

Article / Publication Data
Available Metadata
Fiscal Year
Publication Name
Weather and Forecasting
Published On
August 01, 2005
Publisher Name
Amer Meteorological Soc
Print Volume
Print Number


Not available


Authors who have authored or contributed to this publication.

  • Michael P. Kay - Not Positioned Gsl
    Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder
    NOAA/Global Systems Laboratory