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Tornadic Thunderstorm Types in the Northeastern United States |
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Tornadic Thunderstorm Types in the Northeastern United States
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Perhaps one important misconception meteorologists in the Northeast (and perhaps elsewhere) have is the importance of supercells in the production of tornadoes, at least from a numbers point of view. While it is true that supercells produce the majority of strong and violent tornadoes, many tornadoes are produced by other mechanisms. In this study, supercells (those thunderstorms with significant and persistent circulations) produced only about half (49%) of the 86 tornadoes examined. The tornadic supercells typically exhibited strong rotation. Range and other radar limitations can affect our ability to detect these storms. However, everything (range, scanning strategy, etc.) being equal, supercellular tornadoes are generally easier to warn for as they are usually better developed, larger and last longer. Supercellular tornadoes in this study came in a variety of sizes and shapes. They were observed as lone cells, ahead of lines and embedded within lines. Below is a storm-relative velocity image (Archive Level II) of a classic supercell tornado over Saratoga County, NY on 31 May 1998. The image was taken at tornado touchdown time, 2022 Utc (4:22 pm local time). At this time the maximum inbound velocity was 60 kt and the maximum outbound velocity 49 kt with an overall rotational velocity of about 55 kt. The storm reached F3 intensity shortly after this time. |
