Climatology of Thunderstorms for North Dakota, 2002-06

摘要

Radar and surface thunderstorm data in North Dakota were investigated to obtain the climatology of thunderstorms in the state. A life cycle analysis for the individual storm cells between 2002 and 2006 was carried out, and it was found that June and July were the peak months, late afternoon to early morning was the peak time for thunderstorms, the average lifetime of storm cells was 23.6 min, the average gust wind speed was 16.5 m s~(-1), the average track length was 21.8 km, and the average movementspeed was 16.4 ms-1. The average movement of storm cells varied with months, and the storms moved toward the north, the northeast, and the east. It was also demonstrated that there were 19-35 thunderstorm days each year in North Dakota and that, of these, 9-14 thunderstorm days each year were associated with high speed winds. Severe thunderstorms composed 1.7% of all the thunderstorms in 2002-06. The most intense thunderstorm in North Dakota between 2002 and 2006 was associated with a 5-yr-high wind speed of 31.4 m s~(-1). It was also found that the longer-lasting storms were the stronger storms.