Is This Year's El Niño A Bust?

Tuesday, January 19, 2016
1:42 pm

Average precipitation anomalies from El Niño events. Credit: NOAA

For winter-weather lovers and skiers in the Pacific Northwest, an El Niño forecast sounds like a death sentence. Such a forecast conjures up visions of no major windstorms, hardly any lowland snow, below-average snow in the mountains, and a "death ridge" more often than not firmly situated over our area, giving us fog and poor air quality while sending powerful storms to our north and south.

This has not necessarily been the case for the SUPER strong El Niños (1982-1983 and 1997-1998), and it was not true at all for this November and especially December, where much of Oregon had its soggiest month on record and monthly snowfall records were set throughout the state. Even Washington had record snowfall in some areas, with Snoqualmie Pass picking up over 16 feet in that month. This was due to a persistent ridge in the Eastern Pacific and a trough closer to our area, directing a steady parade of cool storms from the northwest into our area. The result was heavy snowfall all the way down to 1,000 feet, and it was even possible to ski down to Mt. Si, which, despite a summit elevation of 4,167 feet, gets less snow than Snoqualmie Pass because it does not receive a strong, cool easterly wind from Eastern Washington to locally lower snow levels.

As was expected, our pattern transitioned to a more typical El Niño pattern after the New Year with high pressure over us and storms coming to our north and south, but by mid-January, we had entered a slightly wetter-than-normal pattern with weak storms coming in every day or so and putting even more snow in the Cascades. I've been up at Alpental for the past two weekends teaching ski lessons, and there is a TON of snow up there. As the below picture shows, our snowpack is still at or above normal throughout Washington, and well above normal in Oregon, Nevada, California, and southern portions of the Intermountain West and Southwest. It's common for those southern places to have above normal snowfall, but not so much for the northern places.

Credit: USDA/NRCS National Water and Climate Center

In California, many are worried whether this El Niño will give them the massive amounts of precipitation that their local weatherman promised.

Credit: Southern California Public Radio

Credit: Mercury News

Indeed, if you look at the percent of average precipitation from the beginning of the current "water year" (October 1) to present, El Niño's effects in California look rather underwhelming. Meanwhile, the Pacific Northwest has been reveling in heavy rain and mountain snowfall.

Credit: Western Regional Climate Center

This certainly doesn't look like what we'd expect for a super strong El Niño for this period. California typically gets absolutely slammed with precipitation during this time frame, with near-normal to slightly-above-normal precipitation in the Pacific Northwest.

Credit: NOAA Earth System Research Laboratory - Physical Science Division

However, Californians needn't fear. Rain is coming.

Credit: LAist

Credit: LA Times

Since the New Year, the precipitation pattern has looked much more El Niño-esque. Southern California has received near average precipitation, and the folks in Northern California have been getting soaked. We've been drier than normal here in the Pacific Northwest, but a more active pattern over our region during the next two weeks should help put us above normal by the end of the month.

Credit: Western Regional Climate Center

Credit: NOAA Earth System Research Laboratory - Physical Science Division

While California got above average rainfall during the beginning of the month due to a split flow pattern, I expect the rainfall to resume soon and be even heavier for this second time around. We are forecast to again have a split flow off the West Coast, but with a twist. This time around, the northern branch will be much, much weaker, allowing California to experience the full brunt of the storms because the storms will not be "torn apart" by the split. In fact, there may be some times when there is no split at all and a powerful jet stream is slamming directly into California. By February, I expect California to be getting absolutely walloped by storms. That is what happened in 1983 and 1998, and signs are there that it will happen again.

Credit: NCEP

But don't just take my word for it. The Climate Prediction Center is also going with above-average precipitation in California. As a side note, they have consistently underestimated the precipitation in the Northwest, and I would not be surprised if the Pacific Northwest picks up above-average precipitation in this pattern as well. Of course, they are paid professionals and I am just another internet blogger.

Credit: Climate Prediction Center

So no, this year's El Niño is not a bust. It's just a little late to the party.

Charlie