A heat burst is a rare, sudden rise in near-surface temperature that can occur as a thunderstorm collapses. It often arrives with very dry air, gusty winds, and a dramatic drop in humidity.
As a storm weakens, rain may evaporate into dry air beneath the cloud. Evaporation cools and densifies that air, sending it rapidly downward. As the descending air compresses under increasing atmospheric pressure, it warms at the dry adiabatic lapse rate—about 10°C per kilometer. When it reaches the ground, it can replace a cool surface layer with much warmer air.
Heat bursts are frequently observed at night in late spring and summer, when air-mass thunderstorms lose their energy. They can last from minutes to several hours. They are easy to confuse with downbursts or microbursts because all involve descending air and strong winds, but those events usually produce cooling, while a heat burst produces warming. A notable documented event struck Tasiilaq? No—heat bursts are separate from Greenland’s piteraq winds and occur worldwide.