 |
Pulse Severe Thunderstorms Introduction |
|
|
Pulse Severe Thunderstorms
|
Although pulse severe thunderstorms account for a small percentage of severe storm related deaths, injuries and damage, they are generally considered more difficult to effectively warn for due to their short life cycle and isolated nature. This difficulty is evident when looking at warning verification scores for severe thunderstorms. Scores for pulse severe storms are generally lower than those for large, well organized convective events. Earlier work to develop warning criteria (Lemon 1980) for pulse severe thunderstorms was successful in improving these scores when the NWS was using the WSR-57, WSR-74C and WSR-74S radars. However, many of these techniques can not be directly translated to the WSR-88D, due to differences in scan strategies, beam resolution, system sensitivity and display properties (dBZ vs VIP levels). The focus of this study is to try to develop criteria that will allow the warning meteorologist to distinguish between pulse thunderstorms that may become severe, verses those that will not. Due to the short lived nature of these events, many parameters will be examined with an eye toward gaining the maximum amount of lead time possible. To accomplish this, a data-set of pulse thunderstorms from across the Northeast for the years 1995 through 1998 is being assembled. WSR-88D, Level II archive data was used in order to have the ability to create cross-sections and view the highest resolution data possible. Future investigation will include the examination of high resolution satellite data and cloud to ground lightning information in an attempt to increase warning lead time.
|