A microburst is generally taken to be the downpouring of air from a well-developed Cumulus or CB cell. The air does indeed strike the ground and then flows outwards away from the cell. As you fly towards the cell, therefore, you will be going into a 'headwind'. As you transit under the cell, you will have the downdraft, and then as you pass out of the other side, a tailwind. Because of this you will see it is not normal to meet things the other way round.
The changes in wind may well cause lower speed a/c a problem, but the primary concern for passenger a/c like the 757 is the sometimes huge downflow which in some parts of the world can exceed the climb capability of the a/c, and has brought down jet airliners. There is therefore no 'technique' other than to avoid, and yes the cell will be visible on weather radar, so the clue is there although the air movement will not be.