Heat Island
Take a look at this:
Common during the Summer, and much more common over the last 15-20 years, the Heat Island can significantly disrupt developing thunderstorms by creating such strong updrafts that clouds can't move down into the Valley.
This is one of the most frustrating (and common) sat/radar views you will see during the Summer.
Thankfully today it looks like we might be able to overcome the island, as the T-Storms developing to the North and East are looking good.
