From WindsportAtlanta.com: Wiki
The Dome Effect is primarily a spring time effect where a warm breeze skips over the lake because of a pool of cool air just above the water. It is more likely to occur in April and May when the water temperature may still be in the 50s or 60s but the air is well into the upper 70s. It is not uncommon to see flags flying on the trip all the way from Atlanta and have a good wind report from the Gainesville Airport but find little or no breeze at Lake Lanier. Also, a breezy morning while the air is still cool will lure out windsurfers who find less and less wind as the air warms up.
The effect may be most pronounced on the leeward (downwind) side of a body of water as it increases the size of the cold bubble as well as the distance the wind has separated from the surface. Launches that are either sideshore or closer to the windward edge will not be subject as much to the effect. On lakes with windward objects (trees), this may not be much of a help but, in coastal areas, you may find better launches by considering these types of launches instead of the more common onshore launch.
Additionally, stronger winds can temporarily push the bubble off or mitigate its effects. However, in practice, this means that winds tend to be gustier than normal. Lulls are exacerbated by the bubble effect which are then followed by the full power of the wind or its gusts.