In the red shade, those are low 80-degree temperatures. Surrounding that red bulls-eye, there are 60-degree temperatures and into the low 70's. What could possibly cause a 10-degree localized difference in temperature? Well, let's look at the three hour trend.
This shows that temperatures were dropping in most of the state overnight, but then temperatures rose quickly about 10 degrees or more in that localized spot. I looked at radar, and saw that there were thunderstorms moving east through the state that were rapidly weakening. When a thunderstorm "dies" like this, it can produce a dry downburst of cooler, denser air that is "compressionally warmed" as it descends from high up in the cloud to the ground very quickly. Winds can become very gusty, which they were at the time I took the above snapshots of temperature. Gusts were around 45 mph, but had been up to near 60 mph as that dying thunderstorm moved through Central Oklahoma!
This shows that temperatures were dropping in most of the state overnight, but then temperatures rose quickly about 10 degrees or more in that localized spot. I looked at radar, and saw that there were thunderstorms moving east through the state that were rapidly weakening. When a thunderstorm "dies" like this, it can produce a dry downburst of cooler, denser air that is "compressionally warmed" as it descends from high up in the cloud to the ground very quickly. Winds can become very gusty, which they were at the time I took the above snapshots of temperature. Gusts were around 45 mph, but had been up to near 60 mph as that dying thunderstorm moved through Central Oklahoma!
These strong winds are another interesting aspect that make heat burst events so rare. This is because the sinking, warming air must descend faster than the rate at which it is warming. Cooler air is denser than warmer air, and it is that initial density difference that drives the cool, dense air to sink. If it warms, though, it should then be more buoyant than the surrounding air and rise again. But the strong winds descending keep that parcel of air plummeting toward the ground at a rapid pace, so the rapidly warming air slams into the ground with very strong wind gusts.
Heat bursts can occur in the Mid-Atlantic, as well. In fact, there was one on the Eastern Shore of Maryland a few weeks ago. Read about it here.
For a list of other documented heat burst events, click here. And check out another Oklahoma heat burst event that caused temperatures to rise in a matter of minutes at night from 91 degrees to 102 degrees!
Heat bursts can occur in the Mid-Atlantic, as well. In fact, there was one on the Eastern Shore of Maryland a few weeks ago. Read about it here.
For a list of other documented heat burst events, click here. And check out another Oklahoma heat burst event that caused temperatures to rise in a matter of minutes at night from 91 degrees to 102 degrees!
--Carrie
