Pineapple Express to drench California, Stockton

At atmospheric river continues to slam portions of California Tuesday, with multiple inches of rain expected until Wednesday morning.
Weather systems that affect the West Coast of the United States often have their origins in the northern Pacific Ocean. This is because the jet stream usually flows in a general west-to-east fashion.
Two atmospheric rivers have ended Northern California's dry spell, bringing heavy rains and setting records in San Francisco.
Pineapple Express has drenched Northern California in the last few days—but what exactly is it? How common is it? Also, go ...