Heat burst

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A heat burst is rare atmospheric phenomenon characterized by straightline winds and a fast, high increase in temperature. They occur most frequently at night after thunderstorms. While this phenomenon is not fully understood, it is thought that they are caused by masses of extremely dry air high in the atmosphere. Like a microburst, the cooler, denser air sinks rapidly towards the surface, but is far dryer and higher up. With no moisture to absorb the latent heat, friction causes the plummeting airmass to heat up greatly. Temperatures in heatbursts have been known to exceed 110°F (43°C).

Hastings, Nebraska experienced a heat burst during the early morning of 20 June 2006 when surface temperatures abruptly increased from the mid-70s to 94°F.

On 17 July 2006, a heat burst formed in Western Minnesota, pushing Canby's temperature to 100°F, and causing a wind gust of 63 mph. The dew point fell from 70°F to 32°F over the course of one hour. According to National Weather Service discussion of the event, "Research has shown that the radar echoes associated with heat burst activity often take on a thin, wavy, snake-like appearance."

In Portugal in July 1949, a heatburst reportedly drove the air temperature to 158°F from 100°F two minutes earlier (note that the highest temperature formally recognized on the Earth was 136°F in Libya in 1922, although the former record has not been verified).^[1]

In 1960, the town of Lake Whitney, Texas, experienced a heat burst sending the air temperature to 140°F, supposedly causing cotton crops to become desiccated on-the-spot and causing car radiators to boil over.