All MA maps have a 30mph wind layer at 16,000' this layer is 1000' high. Therefore from 16K to 17K this 30mph wind is a factor. The wind is out of the North (heading N to S). You can confirm this by grabbing your favorite fighter and flying to 15,900' and getting a feel for your controls. Then put the plane into a climb and go up to 17,100' while trying to maintain an exact heading. The layer becomes extremely obvious, even more notable if your plane is slow as you enter the layer. If you are heading North one of the things you will notice is a sudden jump in your climb rate (caused by 30mph of extra lift). If you are going South you'll see a sudden drop in climb rate. All of that is an explanation and setup for this fact... the layer is only 1000' tall.
Now as for what effect it has on level bombing above 17,000', it depends. The first factor in the wind layer drift is how high above the layer you dropped your bombs. The second is which direction you are heading when you drop.
The first element, altitude, determines the bombs actual velocity when it hits this layer. Bombs dropped at 17,100' (Ex 1) will be shoved a greater distance by the wind layer because they are falling relatively slowly when they hit the wind layer. Likewise a bomb dropped at 25,000' (Ex 2) will be impacted minimally by the layer since by the time it passes through it will be going quite quickly.
Example 1) Gravity 32' p/sec/sec, distance travelled 100' (insert pain in butt math to determine distance travelled by bomb in last second of fall b4 reaching the wind layer) = 64' p/sec = 43mph
Object w/velocity of 43mph travels 1000' in 15.5 seconds. Annoyingly enough the object is still subjected to a 1G acceleration which causes even my mind to be pained at 7:30 AM while starting coffee # 2 so actual time spent in the layer is (really painful math occurs here) roughly 5 seconds. Spending 5 seconds in a 30mph drift causes objects to receive a shove equal to 219'. This 219' is not the actual amount of drift off target but rather is an element in an change of angular movement equation that I'm not even going to attempt but your starting to get the idea aren't you?
Example 2) {god I hate myself for even replying to this post at 7:30 AM} If the bomb is dropped at 25,000' it has a whole 8K to accelerate to a speed of (insert smell of braincells cooking) 480 mph which means that it will spend a very short 1.5 seconds in the layer and while there is subjected to a shove of roughly 75' which again gets stuffed into seriously obnoxious equation relating to angles and changing them.
The second element I mentioned was actual direction of travel as compared to the wind layer. If you are heading North then the above evil math shows that the bomb will fall short of the actual aim point (has to travel against wind at that point). If you are travelling South the bomb will fall long, if you are travelling East the bomb will be off to the right and last if you are going West it will be left.
What in the **** does all this mean? Have you even reached this point in the description? Well first of all it means if you have a pinpoint target that you need to hit exactly grab a P38/P47/{insert favorite JABO here}. Cause you sure as hell have no hope of hitting a pinpoint target while level bombing above the wind layer. Secondly, "Use the Force", not joking, really if you are determined to hit the pinpoint target from a level bomber than you must get the feel of what that layer is doing to you. Third, it is junk like this that is the reason for salvos and the idea of just blasting the crap out of an area rather than a spot. Fourth, I generally allow for 1 fighter hanger worth of drift at around 20,000'. If I'm aiming for a hanger I drop a full hanger width in whatever direction is dictated by Element 2. Yes, this is what you were originally after when you asked and yes I did put this sentence last. Consider it a test. Did you really want to know?