Rusty,

No. As far as I know they do not give any advanced warning signs. Airports are now equipped with special radars that can detect them and warn aircraft of their presence, but nothing can detect them before they happen.

Most people have seen micro-burst all the time. 90% of them do not have damaging winds. When you are heading toward a storm and you see an area of rainfall that is very well defined, looking like a shaft of rain coming down and clear on both sides. that is a micro-burst.

Sometimes you will note an approaching storm but the wind is blowing toward it, and the storm seems to be moving against the wind... this is the inflow winds at ground level. And is a sign of a powerful storm still in its building stage. as the Heavy thunderhead (Technically a Super-cell) build up, it pulls in surrounding air.. just as a mushroom cloud from a big explosion does.

Just before the rain hits, have you noticed the sudden drop in temp and the increased wind (usually just a strong breeze)? this is the microburst.

I think I am going to post a blog that will demonstrate what it is like to experiance a strong Microburst. I do have both the transcript and the audio from the CVR (Cockpit Voice Recorder) of that Delta flight I mentioned that crashed in Dallas back in the 80's

Damage such as this is not always from tornadoes. Strom thunderstorms, especially what is referred to as supercell thunderstorms can create extremely damaging straight line winds of hurricane force in localised areas. We refer to these phenomena as Downdrafts or Microbursts.

T-storms are created by heat energy. just as Hurricanes are. this energy is stored in the clouds. if a particularly sudden precipiation event occurs within a specific region of the cloud it could suddenly empty that section of its moisture. This sudden release of moisture, and the falling rain itself, strips the air of its heat and rapidly cools a large volume of air.

Now everyone knows that hot air rises and cold air decends. This very large mass of suddenly cold air rapidly decends to the ground. As it hits the ground it spreads out in all directions like ripples from a pond.  The winds associated with the storm can be high, 20, 30, even 40 mile an hour winds, but with this microburst, winds can exceed hurricane force for a very localized area and for only a few moments.

Microburst dont often get this powerful though. for the most part, many people know them as a danger to Aircraft. There have been several very public and tragic crashes of airliners because of microbusts. As a plane flys into a microburts, it encounters a strong headwind (Wind coming from the front of the plane). Airspeed equals lift, so the plane must reduce speed to maintain their flightpath, especially at low altitudes and speeds such as on final approach to land.

As the plane passes the center of the microburst, the winds suddenly shift to a strong tailwind, and the plane, underpowered for the headwind, suddenly finds itself far too slow and the relative airspeed is now below the plane's stall speed. Stall speed is the minimum speed a plane can go and still fly. Below stall speed and the wings do not create enough lift and the plane simply falls out of the sky.

When this happens on approach to landing, the plane may be too low for the pilot to recover in time and a crash occurs.

This is what happened on August 2nd 1985 to Delta Flight 191, an L-1011 on approach to DFW Airport in Dallas during rain showers.

135 people were killed.