"History shows a strong El Niño may mean huge snow for D.C. this winter or almost none"

All or Nothing at all.

We keep getting the question, what does the strong El Niño mean for Washington, D.C. this winter?

During the five strongest El Niños since 1950, winters either featured among the most paralyzing snowstorms in Washington, D.C.’s history or hardly any snow at all.

Why such variation? El Niños tend to have two primary effects on U.S. weather which play out in complicated ways over the Mid-Atlantic: 1) They push the average position of polar jet stream north, which favors warmer than normal air over the region 2) They intensify the moisture supply along the southern jet stream, increasing the potential storminess.