The other day a decaying complex of thunderstorms approaching western and northwestern Oklahoma from the Texas Panhandle produced a phenomenon known as a heat burst across northwestern Oklahoma late that night. Temperatures rose as much as 20 degrees within minutes followed by an equally dramatic decline in dew point temperatures. Strong wind gusts over 60mph at times were reported. There were no reports of any damage but there were a lot of questions raised about this phenomenon.

What: A heat burst describes the sudden downburst of hot and dry winds from a dying thunderstorm reaching the surface. This natural phenomenon is almost always associated with a dramatic increase in temperatures and equally dramatic decrease in dewpoints. They are also followed by a prolonged period of high winds which can gust up to 100mph in extreme cases. There have been instances where the temperature has soared well into the 100's during the wee hours of the morning. Thursday night's heat burst featured temperatures that warmed into the upper 80's and lower 90's. The highest temperature was recorded in Harper county where a reading of 93 degrees was measured.

How?:

Heat bursts are induced by a decaying complex of thunderstorms. Heat bursts are more common in the late spring and early summer and most likely in the plains states. However heat bursts can occur almost anywhere. During the day a hot and humid air mass usually generates thunderstorms, sometimes these storms can grow upscale into what is called a complex of thunderstorms. Once the sun sets and with the loss of diurnal heating, the atmosphere stabilizes and surface heating and instability decreases. This causese the upward motion in the thunderstorms or the updraft to shut off. Precipitation will continue to fall and evaporate cooling the air. Once the storm "rains itself out" the cooled air compresses and rapidly heats up, releasing a voilent downdraft of hot and dry air to the surface. This air is then spread outward from the decaying downdraft and results in a heat burst.

This pavilion for August 8. 2008 in Sioux Falls, SD shows a classic heat burst. Notice how the temperature shortly before 4am at 75 degrees reaches a peak of 100 degrees shortly after 4am. This is an incredible 25 degree rise in temperature! Notice how at the same time the dew point which was almost equivalent to the temperature decreases sharply into the lower 50's as the heat burst was taking place. With time you will notice that the temperature decreases and dew point increases as the effects of the heat burst fade. There were likely strong wind gusts, possibly exeeding hurricane force during this particular heat burst as well.

Can we predict heat bursts? Actually yes we can. Advances in technology and forecasting have allowed us to make a prediction on where these events may occur. Knowing where a thunderstorm complex may form and the conditions following its development can help the forecaster predict if and where a heat burst may form. In most cases heat bursts cause little to no damage, but there have been some extreme cases where there has been significant damage due to high winds. Because these events do not happen often, they make for an interesting experience when they do occur.