El Niño was noteworthy, but not for the predicted reasons
As the near-record 2015–16 El Niño continues to diminish — it’s now weak to moderate — it’s worth seeing if pre-winter predictions and hype lived up to reality.
At least one observant reader recently pointed out that meteorologists and journalists spun El Niño predictions in a variety of sometimes-contradictory ways. Though last fall’s long-range forecast of a warmer-than-usual winter was quite accurate, precipitation in the Pacific Northwest was variously predicted to be “below average,” “higher than normal,” “dry” and “less.”
As we now know, our local winter rainfall was impressively heavy virtually from start to finish. From Jan. 1 through the start of spring, rain at Astoria-Warrenton airport was about 10.5 inches more than average. Winter totals approached a foot of rain per month. (Since late-March, the weather has dried out, but we’re still around 7 inches above normal for the calendar year.)
Meteorologists are careful to couch seasonal predictions in broad terms, and this El Niño was clearly one that defied even the usual nuanced language when it came to rain in the Northwest. There is some commentary in academic circles to the effect that the strength of 2015-16 El Niño and other climatic factors kept Pacific storms more focused on Oregon and Washington, instead of shifting to Southern California after Jan. 1 as had been predicted.
Insurance brokers, who bear real-world financial consequences of weather events, are perhaps the best judges of forecasting accuracy. An analyst for the BMS Group of brokers on April 6 observed, “Climate forcers like El Niño and La Niña can help predict the frequency of overall weather activity, but truthfully, [making totally accurate] long-term predictions about ... the power of severe weather is impossible.” El Niño is only one of several atmospheric cycles, all of which interact to create seasonal weather, the analyst noted.
Looking at the North Pacific as a whole, the NOAA-West Watch blog (tinyurl.com/NOAA-WESTWATCH) observes El Niño certainly did inject a lot of additional energy into the ocean system and the weather it delivered to our shores.
• Record waves battered West Coast shorelines: “approximately 45 percent more wave energy than normal hitting West Coast beaches, with about 40 percent more erosion than the average for the similar winter time frame.”
• Rough conditions slowed Columbia ship traffic in December: “Pilots suspended shipping traffic across the Columbia River Bar nearly 10 times in the month of December, among the most closures in a single month that most pilots could remember.” Conditions were much more moderate after Jan. 1, however.
• A warm-water algal bloom off Chile has killed more than 27 million farmed salmon, leading to a predicted “global supply shock” in coming months. As we know all too well, here in the northern hemisphere a similar warm-water algal bloom damaged crab and razor clam fisheries last fall and early winter.
Looking at all this, El Niño clearly was worth the headlines last fall — but not for all the reasons journalists reported. Skeptical readers are right — even a strong consensus of scientists sometimes can get it wrong.