http://www.usatoday.com/story/money/columnist/2015/05/15/el-nino-extreme-weather-commodities-futures/27356169/Heavy rains in San Diego in May are very rare. And heavy rains in the desert southwest in their dry season are rare.
Plume after plume of deep tropical Pacific moisture keep feeding over northern Mexico into Arizona, New Mexico, Colorado, and Texas. And there are pockets of sub surface water some 7°C above normal near the coast of Ecuador...while the sea level has dropped a foot east of the Philippines...indicative of a strong El Niņo event.
Typical strong El Niņo impacts:
Monsoon failure in south/southeast Asia
Drought in Australia
Drought in the Amazon
Drought in the Pacific Northwest
Flooding in the deserts of Peru and Chili
Flooding in the Mexican and SW American deserts
Mudslides in California
Cool and wet in the southern US
Warm during winter across the northern US
Heavy rains in the horn of Africa
Fewer Atlantic hurricanes
Enhanced western US summer monsoon
More eastern Pacific hurricanes
And myriad tertiary impacts everywhere else that disrupt normal weather patterns.