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In meteorology, a heat burst is a rare atmospheric phenomenon characterized by gusty winds and a rapid increase in temperature and decrease in dew point (moisture). Heat bursts typically occur during night-time and are associated with decaying thunderstorms. Although this phenomenon is not fully understood, it is theorized that the event is caused when rain evaporates (virga) into a parcel of cold dry air high in the atmosphere making the air denser than its surroundings. The parcel descends rapidly, warming due to compression, overshoots its equilibrium level and reaches the surface, similar to a downburst.〔 〕 Recorded temperatures during heat bursts have reached well above , sometimes rising by or more within only a few minutes. More extreme events have also been documented, where temperatures have been reported to exceed . However, such extreme events have never been officially verified. Heat bursts are also characterized by extremely dry air and are sometimes associated with very strong, even damaging, winds. ==Characteristics== In general, heat bursts occur during the late spring and summer seasons. During the late spring and summer seasons, thunderstorms tend to generate day heating and lose their main energy during the evening hours.〔National Weather Service Albuquerque, NM Weather Forecast Office. "Heat Bursts". Retrieved from http://www.srh.noaa.gov/abq/?n=localfeatureheatburst〕 Due to a potential temperature increase, heat bursts normally occur at night. In rare cases, heat bursts have been recorded to occur during the daytime as well. Heat bursts have lasted for times spanning from a couple of minutes to several hours. The rare phenomenon is usually accompanied by strong gusty winds, extreme temperature changes, and an extreme decrease in humidity. They occur near the end of a weakening thunderstorm cluster. Dry air and a low-level inversion are also present during the storm.〔(【引用サイトリンク】title=All About Heat Bursts )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Heat burst」の詳細全文を読む スポンサード リンク
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