ok so this one has me really intrigued…I understand the science behind sinking air heating up, but I had never heard of this before this blog…repeat, Bonzo is intrigued!
A rare and intense heat burst affected south-central Nebraska early Tuesday morning rising the temperature from 73?F at 2 a.m. to 97?F by 4 a.m. in Hastings. Herein is a summary of the event and other notable heat bursts that have occurred in the past.
Between 1 a.m. and 4 a.m. CST on June 11th dissipating thunderstorms in the Grand Island, Nebraska area created conditions conducive to the development of heat bursts. At Grand Island the temperature rose from 73? (2:53 a.m.) to 90? (3:37 a.m.) and at Kearny from 75? (12:55 a.m.) to 97? (3:15 a.m.). Holdrege and Lexington also saw sharp temperature increases, but Hastings seems to have measured the most pronounced effects with its 24? rise from 73? to 97?.
What Causes a Heat Burst?
The NWS office at Hastings published a statement Tuesday morning that included a very good explanation of what causes heat bursts to occur. I quote here:
A heat burst is caused when a shower or thunderstorm weakens over a layer of dry air. As the last of the precipitation from the weakening shower or thunderstorm falls through the layer of dry air the precipitation begins evaporating thus causing the air to cool. As this air cools it will become more dense…eventually more dense compared to the surrounding warmer air and as a result begins descending to the surface at a high rate of speed. Eventually all of the precipitation within the descending air evaporates. At this point the air is completely dry and because no more evaporation can occur the air can no longer cool. The air, however, continues to descend towards the surface due to the momentum it has already acquired. As dry air descends through the atmosphere compression due to increasing atmospheric pressure causes the air to warm. It is important to note t
Interesting. I have family in Grand Island, Giltner and Hastings Nebraska. I thought they only had to dodge tornados and snow on the ground from Thanksgiving to Easter. Interesting Phenomenon.
Interesting that it only seems to happen in the wee hours of the morning
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thank you, Optiker, for your intelligent input into this conversation
my guess as to the overnight hours phenom is due to storms typically losing their punch after the sun goes down…
A heat burst is caused when a shower or thunderstorm weakens over a layer of dry air.</font id=“green”>
and Ricky, Cliff Notes: temps rising some 20-30 degrees in minutes because of strong downburst of air from weakening storm or shower…
