Heat Bursts

[bubba]

These events are sometimes called Heat Flashes and cause a super increase in temperature that lasts for several minutes.Many times they occur at night and near Thunderstorms.Examples include !52F. at Antalya,Turkey on July 10,1977;temperature escalation from 100F. to 158F. in several minutes near Lisbon,Portugal on July6,1949 and an unbelievable report of 188F.during June 1967 at Abadan,Iran in which asphalt liquefied and numerous people were killed.Any Heat Bursts in your neighborhood recently?

[mppalms]

Well, you made me look.  I didn't think such extreme temps were possible, but I suppose if RH is low enough, the temps in a column of falling air can rise quite fast and to very high numbers.

Jason

[bubba]

Bubba thank you for your acceptance notwithstanding urge to say Bubba tell a lie.Does anybody on Board live near Lake Whitney Northwest of Waco,Texas.If so,Bubba request exploratory commitee to be enlisted to discuss with folks an occurence of said Heat Burst just after midnight on June 15,1960.Said temperature jumped from pleasant 70F.to a toasty 140F.leaving carbonized cotton fields with only burnt stalks standing.

[FRITO]

wow never heard of such a thing. sure it isnt aliens in the sky shooting down lazer guns?

[bubba]

One Million Dollars!

[steve 9atx]

Yea, Bubba, my mom used to talk about this phenomenon quite a bit 25 years ago......

Steve

[osideterry]

I've experienced 50F temp raises in 5 hours a number of times, but never heard of it in minutes. I recall reading in the Guiness Book an account of a sudden massive drop in the 1900s, that caused a tornado out nowhere.

[bubba]

All kidding aside,Heat Bursts are a scientifically recognized phenomena.Colorado State researchers Ben Bernstein and Richard Johnson explain the phenomena in the Monthly Weather Review issue of February 1994 as follows:

              "The heat burst,near remnants of thunderstorm clusters,is a downburst of air from the thunderstorm displacing a shallow pool of cool air hugging the ground.The phenomenon is akin to what would happen if one blew strongly down onto a shallow puddle of water;the puff from your lungs temporarily clears water from a spot on the surface."

[PalmGuyWC]

Until this thread I had never heard of a heat burst, but as a pilot I sure know what microburst are. There are microburst detectors stationed around many major airport and pilots are told to avoid them as they have caused many accidents. One of the most notable was the Delta Airlines crash at DWF many years ago. Microbursts are associated with virga, rain coming from a cloud which evaporates before it reaches the ground. The rapid evaporation of the moisture cools the air which is much more dense than the surrounding air mass and it decends very rapidly, sometimes up 100 mph..

Once when I was flying into Phoenix AZ on a hot afternoon there were many small thunderstorms in the vicinity just east of the airport. We observed virga and soon small colums of rapidly decending air hit the ground. These were only about 1/4 to 1/2 a mile in diamater. As they hit the dusty ground they were easy to see and as the dust was blown it looked like very well formed doenuts of dust with wind spreading out from all sides. We cut inside of the doenuts and landed to the west without incident.

We didn't have jet ways in Phoenix at that time, so we had to walk across the ramp to get to the terminal. By the time we taxied back to the deboarding area a microburst moved over us and there was an instant dust storm with debris being blown around with very strong winds. We had to delay the deboarding until the microburst moved away which was only a few minutes.

Once flying into Denver on final approach we inadvertanly flew into a microburst, as this was before they had the reporting instruments installed at the airport.  Most times they are not visable and the wind direction and speed can change in an instant. Even though we were decending with flaps out, gear down, it took full engine power to stay on the glide slope. Just a few hundred feet from touch down we flew out of the microburst and landed normally.

After the incident with Delta at DFW, we were taught new procedures and told not to land if microburst were observed over the airport. In fact after the microburst instruments wrere installed, the control tower would shut down the airport until the microburst moved away. Flying into 100 mph  decending wind can be fatal, especially close to the ground.

Dick

[bubba]

Dick,You are the kind of Pilot I wish I could request everytime.Sadly,I knew four people from West Palm who were killed in the Dallas crash.The plane flew out of PBIA.I bet you saw alot of incredible stuff.Any Ball lightning down your aisles?