From fall until spring, Southern California was supposed to experience one of the strongest El Niño weather patterns in a century. Warnings of flooding and road washouts prevailed throughout the fall.

Although the precipitation since July 1 has exceeded recent years, it remains less than the long-term average. El Niño failed to dampen the spirits of Southern California residents.

Last week, Alex Tardy, meteorologist for the National Weather Service’s San Diego office, offered some explanation for the missing rain.

The ocean conditions, much warmer than normal water temperatures, occurred and presaged the strong El Niño. However, the atmospheric conditions were different than during the 1982-83 and 1997-98 El Niño seasons.

The only major storm this winter occurred the first week of January. The atmosphere partnered with the ocean to allow wet air to be pulled across the Pacific Ocean and then over California.

But after that event, the jet stream seemed to split. A strong and persistent high-pressure zone remained offshore, which deflected the storms further north and south, resulting in another relatively dry winter.

The Hill still received about 75 percent of normal precipitation but most other Southern California areas received less. For example, Santa Ana had 33 percent of normal, and Riverside and Palm Springs felt only half the normal rainfall.

“For most of the winter, the high was over California. The storms were still going across the Pacific, but as they reached California, they split, leaving us in a dry zone,” Tardy said. “They completely missed us and went north.”

Northern California received enough rain and snow this winter that the state has raised water allocations for communities that rely on the State Water Project. Many reservoirs are at 80 to 90 percent of capacity. Users should expect 60 percent of allocations, which is the highest since 2012, and compares to 20 percent last year.

The Association of California Water Agencies has recommended that the State Water Resources Control Board rescind its emergency regulations.

“… [D]rought conditions have been substantially alleviated by this winter’s welcome precipitation and snowpack,” the ACWA said in its April 14 letter. “Although precipitation and snowpack conditions may be only ‘normal’ or even somewhat ‘below normal’ in some regions, sufficient surface water supplies are clearly available to water agencies statewide such that storage is being fully replenished and the drought emergency has been substantially alleviated.”

Tardy had other good news. The northern storms did help the rest of the West and the headwaters of the Colorado River.

El Niño is rapidly decreasing, according to Tardy. NWS’ latest long-range forecast says that “… the chance of La Niña increases during the late summer or early fall. The official forecast is … also supported by a historical tendency for La Niña to follow strong El Niño events.”

La Niña conditions are created by colder water temperatures and generally produce drier-than-normal conditions in Southern California. It is too early to expect this to occur and the drought to continue.