All tornadoes — whether small or large — originate from thunderstorms, but not all thunderstorms are the same. Different environments and situations create forecasting challenges. For instance, nighttime twisters, summer tornadoes and smaller events can be tougher to forecast.<\/p>\n
Researchers wanted to quantify how much tougher, and have published a new method of classifying tornado environments according to their forecast difficulty.<\/p>\n
In a new paper published online in the\u00a0Bulletin of the American Meteorological Societ<\/em>y<\/a>,\u00a0University of Washington scientist Alexandria Anderson-Frey, and Harold Brooks from the NOAA\u00a0National Severe Storms Laboratory<\/a>\u00a0describe a new way to rate and possibly improve tornado warnings.<\/p>\n \u201cWith this research, we\u2019re trying to find ways to truly level the field related to the difficulty of the forecast situation,\u201d said Brooks. \u201cThis will help us identify areas for research, as well as better understand the long-term historical statistics.\u201d<\/p>\n \u00a0The paper presents a new method to rate the skill of a tornado warning based on the difficulty of the environment. It then evaluates thousands of tornadoes and associated warnings over the continental United States between 2003 and 2017.<\/p>\n The NOAA-funded study finds that nighttime tornadoes have a lower probability of detection and a higher false-alarm rate than the environmental conditions would suggest. Summertime tornadoes, occurring in June, July or August, also are more likely to evade warning.<\/p>\n \u201cThe forecasting community is not just looking at the big, photogenic situations that will crop up in the Great Plains,\u201d said Anderson-Frey, the lead author. \u201cWe\u2019re looking at tornadoes in regions where vulnerability is high, including in regions that don\u2019t normally get tornadoes, where by definition the vulnerability is high.\u201d<\/p>\n The technique could be applied to forecasts of other types of weather as well.<\/p>\n This research began while Anderson-Frey was a postdoctoral researcher at the\u00a0Cooperative Institute for Mesoscale Meteorological Studies<\/a>, a partnership between\u00a0the University of Oklahoma and NOAA.<\/p>\n