Will This Strong El Niño Take Away Your White Christmas?

The El Niño of 2015 is one of the strongest on record, dating to 1950, and, by some metrics, may already be stronger than the previous strongest El Niño of 1997-1998.
This periodic warming of the equatorial eastern Pacific Ocean can have a number of effects on weather around the world, from heavy rain to extreme drought, persistent warmth to stubborn cold, and inactive versus hyperactive tropical cyclone seasons.
Given its strength, will this El Niño factor into your chances of seeing a White Christmas?
First, it's worth noting that meteorologists define a White Christmas as one in which at least one inch of snow is on the ground on Christmas morning – and they aren't as common as you think, even in colder climates.
Based on 30-year average data from 1981-2010, the chance of at least one inch of Christmas snow cover is less than 50 percent in these traditionally snowy cities:

• Boston: 21 percent
• Pittsburgh: 30 percent
• Chicago: 42 percent
• Cleveland: 45 percent
• Detroit: 46 percent
• Milwaukee: 48 percent

The chance of a White Christmas in any year, based on 1981-2010 data. (Climate.gov)

Even in areas you expect a White Christmas to be a slam dunk, the chances aren't 100 percent, such as Minneapolis/St. Paul (77 percent) and Burlington, Vermont (72 percent).
With that context, let's first examine what happened in December during the previous five strong El Niño events.