San Diego formed an El Niño working group with members of every city department as this winter’s El Niño snow forecast and storm outlook pointed toward possible flooding, sparse rainfall and monster waves. Assistant Fire Chief Robert Rezende is leading the planning, and the city is focusing on neighborhoods near creeks, rivers and lakes.
Rezende said, “From San Ysidro all the way up to Sorrento Valley and Lake Hodges, anywhere there are creeks and rivers and lakes, you have to keep a close eye on those areas to ensure we’re prepared for an extreme weather event.” Tyler Rodenbaugh, a senior meteorologist for the San Diego County Water Authority, said scientists call an El Niño event when sea surface temperatures rise one-half degree Celsius above normal and label it a very strong El Niño at 1.5 degrees above normal.
Robert Rezende and San Diego
That threshold is the one scientists are seeing now, and Dan Cayan, a researcher at Scripps Institution of Oceanography, said large El Niños tend to tilt the odds toward more winter north Pacific storms and larger ones, “because of the energy imparted to the atmosphere from the ocean.” San Diego is preparing across departments because the forecast includes more than one kind of hazard: flooding in some places, sparse rainfall in others, and waves that can damage shoreline areas.
The city’s planning also reflects older infrastructure. San Diego has aging stormwater systems and century-old dams, which puts more pressure on crews watching creeks and low-lying areas during a winter that could deliver fast changes from storm to storm.
Lindbergh Field Rain Totals
Past El Niño seasons show why the city is treating this one as a wide-ranging threat. San Diego had 70 wet days in 1982-83, compared with 40 to 45 wet days in a normal year, and Lindbergh Field at San Diego International Airport recorded nearly 20 inches of rain that year.
The 1997-98 El Niño also brought nearly 20 inches at Lindbergh Field. By contrast, the 2015-16 Godzilla El Niño produced slightly drier conditions, with 8 inches recorded there. A typical year at Lindbergh Field brings 10 inches of rain.
Alexander Gershunov on storms
Alexander Gershunov, a research meteorologist at Scripps, said, “What actually will happen depends on specific storms called atmospheric rivers, which do not dance to the tune of El Niño.” That leaves the city preparing for a range of outcomes rather than a single forecast, with the practical focus on the places Rezende named and the weather systems that reach them.
For residents near San Ysidro, Sorrento Valley and Lake Hodges, the city’s next step is not a date on a calendar but closer monitoring of the streams and lakes most exposed if the storms line up.
