The reason we call these "Persistent Slabs," is because, well, they are persistent. Once loaded with weight, they continue to produce avalanches for several days, which make them especially tricky. For this reason, they are responsible for almost all our avalanche accidents.
Check out the VIDEO I did yesterday on the huge avalanche some skiers remotely triggered on Sunset Peak on Sunday.
Take-home point: Avoid the upper elevation, shady aspects. All the other slopes are quite stable. The avalanche danger in these areas is CONSIDERABLE, meaning that human triggered avalanches are LIKELY and they can be quite dangerous.
Reason: Even though there was only about 6 inches of snow left over from October, it rotted because of temperature gradient metamorphism into very weak, sugary crystals. The sun melted it off all the sunny aspects, so the only places where it remained before the storm was above about 9,000' on northwest, north and northeast facing slopes. When the large amounts of new snow overloaded that weak layer, it produced large avalanches.
Note: on the rose diagram, the blue color represents the places where you will MOST LIKELY find the avalanche problem, not all the places where you will find it. For a more detailed tutorial on how to read the advisory, click HERE. For a rose with the avalanche danger plotted on it, click HERE.