Weather forecasters predicted a “historic" blizzard would dump up to three feet of snow on New York City. Instead, the city escaped the worst of the storm. The National Weather Service admitted Tuesday it was off due to the challenging nature of winter-storm weather prediction: "Our science has come a long way, but there are still many moving parts in the atmosphere, which creates quite the forecast challenge."

On Twitter, conservatives jumped at the opportunity to compare weather forecasts to climate change models:

This myth is routinely debunked, but one more time doesn’t hurt: Weather is not climate. The weather is immediate conditions—rain, snow, sunshine, etc.—while the climate is long-term trends. A blizzard or a cold snap doesn't disprove climate change. It doesn't cancel the fact that ten of the hottest years on record have occured since 2000, with 2014 as the the warmest yet.

Weather forecasts are also not the same as climate projections, because weather predictions are short-term by nature. And despite improved forecasting over the last few decades, weather forecasts are only as accurate as meteorologists' initial data, like atmospheric conditions, ocean surface temperatures, and how well real-world physics is represented in their models. Imperfect knowledge of those conditions makes weather predictions highly variable. 

Climate models, on the other hand, can't predict the weather on a specific day, but they do show trends and averages. They deal with different data, including conditions of the deep ocean, vegetation, and the sun, and how greenhouse gasses impact the system. “The ability (or not) of predicting a single storm on a given day in a specific portion of the U.S. has little relevance to skill in predicting long-term climate associated with long-lived greenhouse gases,” Norman Loeb, an atmospheric scientist with NASA, said in an email. 

There is still a relationship between extreme winter storms and climate change, just not the one climate deniers think. “The oceans are warmer, sea temperatures and sea level are higher because of climate change, and this means the air over the oceans is warmer and moister than it would otherwise be, and that affects all storms,” said Kevin Trenberth, a climate scientist with the National Center for Atmospheric Research. The 2014 National Climate Assessment noted how heavy storms in the northeast have increased 70 percent in the last six decades. 

Climate deniers upset that Tuesday's blizzard skipped New York City can take comfort that the city will face more historic storms in the future.