For long-range forecasting there are few events that are more reliable than an El Nino or La Nina to help make accurate forecasts for future months. We are still seeing conditions line up very well this year for a strong, if not historic El Nino in the months ahead.
An El Nino event is when the water near the equator is much warmer than normal, leading to wetter winters for the West Coast. A La Nina event is when the water near the equator is cooler than normal. It often changes global weather patterns. When combined with big and consistent surf, damage to property and deaths often come with extreme El Nino conditions.
For California, two rainy seasons stick out for their pure power and monster amounts of rain and snow: 1982-82 and 1997-98. Both of those seasons saw massive storms with power that produced huge surf, heavy rain, flooding, mudslides and very heavy snow. During these events widespread flooding and erosion takes place at beaches where raging rivers that meet the sea.
For a primer on what we might be in for this winter it's worth reading thisarticle from March 1998. It's written by a climatologist in the moment after a series of storms hammered the western U.S. in January and February 1998. Here is just one excerpt:
"The rains were not only heavy but persistent. Eureka recorded 26 days with measurable rain in January, and another 26 days in February. San Francisco counted 24 in January and 22 in February. Blue Canyon had 21 and then 25, with 12 and 10 days respectively exceeding one inch. The lack of any significant letup in rains allowed almost no days for drying. Each period of heavy rain sent more earth sliding to lower elevations at a number of locations in the central and south part of the state."
We can only survive in California with large amounts of rain and snow in the winter months, but we can get to a point in an El Nino season when widespread damage can limit the benefits. It may bust the drought, but we may see a lot of damage as well.
The forecast for NOAA show a more than 50 percent for seeing an El Nino this year, and up to 70 percent likely according to climatologists in Australia. In addition to an El Nino, there is something much more serious brewing as well.
That image shows how the water in the Pacific at the equator is trending to be much warmer than average for the last month. This has prompted an El Nino Watch from NOAA. Conditions are ideal for an El Nino to develop later this summer in the fall.
What is more concerning is this image:
This image from NOAA shows that there is a very large area of very warm ocean water just below the surface that could really accelerate El Nino conditions. As this bubble of warm water begins to come to the surface it will interact with the atmosphere and begin to influence the weather. This is the largest and warmest sub-surface pocket NOAA has seen in March since 1979.
As the months tick away, the trend is for more warming at the surface, and more El Nino conditions.