Illustration of a microburst.

Note the downward motion of the air until it hits ground level. It then spreads outward in all directions. The wind regime in a microburst is opposite to that of a tornado.   

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Compiled by A Khokar    July    27, 2010                                       

Aviation security of USA is of the opinion that Keeping in view the sudden crash of the Air Blue aircraft, it is presumed that owing to the bad wet weather and with very low clouds, the phenomenon of ‘Wet Micro  Burst’ occurred which is often a very localized column of sinking air, producing damaging divergent and straight-line down ward winds at the surface that are similar to, but distinguishable from, tornadoes which generally have convergent damage.

 The scale and suddenness of a microburst makes it a great danger to aircrafts due to the low-level ‘wind shear draft’ which  may cause a sudden plunge by its gust front and Aircraft may not remain air borne.

Several fatal crashes have been attributed to this phenomenon over the past several decades.

Illustration of a microburst.

Please note the downward motion of the air until it hits ground level. It then spreads outward in all directions. The wind regime in a microburst is opposite to that of a tornado.

Once any unfortunate air craft enters in ‘Microburst Zone, air craft is sucked down and finds nothing to hold on or to keep  itself air borne; it hits the ground with such a massive impact that it is shattered into pieces—- as we have witnessed in this Air Blue disaster; where as aircraft hiegt was minimal  but  non of the parts like fuselodeg etc are seen intact..

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Up dates  july 29, 2010

What is Microbursts

Downburst less than 2.5 miles in diameter

A downburst is a strong downdraft which includes an outburst of potentially damaging winds on or near the ground. If the diameter of the downburst is less than 2.5 miles, it is called a microburst. The diagrams below depict the evolution of a microburst.A microburst initially develops as the downdraft begins its descent from cloud base. The downdraft accelerates and within minutes, reaches the ground (contact stage). It is during the contact stage that the highest winds are observed. During the outburst stage (above), the wind “curls” as the cold air of the microburst moves away from the point of impact with the ground. During the cushion stage, winds about the curl continue to accelerate, posing a great threat to nearby aircraft.These are very weak, high based showers without thunder, but with microbursts. Studies have shown that they predominantly occur in the High Plains and western U.S.: particularly in unstable, very dry low level environments with surface temperature-dew point spreads of 30 to 50 degrees and an area of mid-level moisture as a source

for the weak showers.

Photograph by: Moller

 The cloud on the left is developing, whereas the fuzzy anvil on the right has matured and is producing a trail of virga. Microbursts would be most likely to occur beneath the virga, when the downdraft reaches the ground. Several of these virga showers did produce microbursts in the Lubbock, Texas area.

Photograph by: Moller

The same day, near the Lubbock Airport, we see several of the small microbursts which emanated from the virga patch in the upper right corner of the photograph. Wind shifts of 35 to 40 MPH were noted shortly after this time, with a rapid onset and cessation of the wind gusts.