88th Annual Meeting (20-24 January 2008)

Monday, 21 January 2008: 11:30 AM
A formal evaluation of storm type versus storm motion
223 (Ernest N. Morial Convention Center)
Jose Miranda, Univ. of Missouri, Columbia, MO; and N. I. Fox
Poster PDF (396.8 kB)
In order to predict the location of heavy storm generated rainfall that could produce flash flooding, forecasters want to know with what velocity a storm will move. However, few systems exist in meteorology where a storm is classified by type, and subsequently, forecasted for motion. This paper focuses on identifying the ambient environmental characteristics typical of several types of severe convective storms.

Three types of severe convective storms are examined: supercell, linear, and multi-cell. Ambient winds at critical levels are noted to obtain a wind profile for eighteen total cases throughout the eastern United States. These cases are then analyzed through an auto-classifying nowcast system and motion is forecast up to an hour in advance. Previous studies have shown that supercell thunderstorms to move with the anvil-level winds; linear storms with the 500-hPa wind; and multi-cellular storms with the lowest critical level winds, which implies storms with the strongest (weakest) vertical updrafts will have motion coherent to the highest (lowest)-level winds. However, the findings of this study show that there is more complexity to predicting storm motion, and in many instances careful selection of the level(s) of the wind to use is critical.

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