New computer models suggest that the current El Niño formation brewing in the Pacific could become the strongest in recorded history. The latest data from the National Weather Service’s North American Multi-Model Ensemble indicates a greater-than 95 percent chance of a strong El Niño and a greater-than 60 percent chance of the strongest El Niño on record.
The broad swath of warmer-than-usual seawater is spreading and deepening. The two largest concentrations are off the coast of Peru, where water is 4 degrees Centigrade warmer than usual, and just west of Vancouver and Seattle — 3 degrees warmer.
If this El Niño continues to grow, it could surpass the modern record-setting 1997-98 El Niño event, which inundated the Bay Area and the rest of California for months, causing flooding, mudslides and subsidences, and heavy snowfalls in the Sierra.
But Jan Null, certified consulting meteorologist with Golden Gate Weather Services, cautions that those scenarios are based on only one of many models. “We don’t know if one model is better than any other,” said Null, who noted that strong ocean warming trends have occurred before in the summer only to have the El Niño fizzle out in the winter.
While El Niño is associated with warming in the southern Pacific, Null is also keeping an eye on the temperature rise in the Gulf of Alaska, which he said is unprecedented. “We don’t know what that means,” he said.
Typically, a robust El Niño phenomenon indicates heavier than normal rainfall in California in the fall and winter, a mild Atlantic hurricane season, a warmer than normal winter over major parts of the U.S., and a very active hurricane and typhoon season in the Pacific.
Null said we would need two and a half times normal rainfall (23-24 inches is the norm) to erase the current drought deficit, something that has never happened. Even in the modern-record El Niño of 1997-98, California received only 47 inches. A powerful El Niño would almost ensure that 2015 will be the warmest year on record.
http://www.sfgate.com/science/article/Worse-than-97-8-New-El-Ni-o-growing-into-6404076.php