STORM2K

Can someone make a graphic or explain what Wind Shear is?

Wind shear is simply the change in direction and/or speed of wind. For tropical purposes, we're often speaking of vertical shear, which is the change in winds with height.

Most of the conceptual models I see on a quick glance of google and bing image searches aren't very good, but I guess this one isn't too terrible

There is also horizontal wind shear which is the change of wind velocity (speed and/or direction) with horizontal distance. Horizontal shear helps generate vorticity (rotation) and can be a trigger for cyclone development. Earth's vorticity (Coriolis) decreases with decreasing latitude from the Poles and becomes ineffective at generating low level rotation at latitudes equatorward of 10 degrees. However, the horizontal shear associated with monsoon troughs can result in rotation developing at latitudes as low as 5 degrees (N or S) or even lower on occasion. This is common in WPAC during the early and late parts of the year.

Steve