The weather pattern across the United States has been a stubborn one, bringing round after round of stormy weather into the Pacific Northwest, while the South, East and parts of the Ohio Valley experience spring-like warmth. So far this year, little — if any — snow has fallen in typically snowy spots such as Buffalo, Burlington, Boston and Portland, Maine.

For the millions of people living east of the Mississippi River who are hoping for a while Christmas, or at least some seasonably appropriate cold weather, it's going to be a disappointing holiday season. Computer model forecasts show an unusually stark contrast between the cooler-than-average weather in the West compared to temperatures across the East that will reach up to 30 degrees Fahrenheit above average between Dec. 22 and 28.

In fact, it's possible that several locations will set records for the mildest Christmas Eve and Christmas Day on record.

The mild December weather is consistent with what forecasters expect during winters with strong El Niño years, since that Pacific Ocean climate phenomenon favors warmer-than-average winters along the northern tier of the U.S. Other factors, including the Arctic Oscillation, which is a weather pattern involving low pressure circulating around the North Pole, are also involved in this setup.

Temperature anomaly forecast for Dec. 22 to Dec. 28, 2015. Image: NOAA/CPC

Some seasonal climate forecasters were expressing their amazement with this weather pattern on social media, including Michael Ventrice, who is a forecaster at WSI Corporation, now a part of IBM.

One of the most impressive Christmas Eve temperature anomaly maps I've ever seen at this lead time. Record Warmth. pic.twitter.com/zsZQMcYTLp — Michael Ventrice (@MJVentrice) December 14, 2015

Year over year snow content in the Northeast = lol pic.twitter.com/ZrNJPUKDAL — Matt Lanza (@mattlanza) December 14, 2015

These departures for the month thus far are flat out nuts. +11.3°F in NYC, +9.1°F Boston, +12.4°F in Chicago! pic.twitter.com/uMftO6yg7T — Ed Vallee (@EdValleeWx) December 15, 2015

According to Ventrice, 18 states have seen temperatures greater than 9 degrees Fahrenheit above average thus far in December.

"Cherry-picking a city, our current Max Temperature Forecast for New York City (65F) on Christmas Day would break the all-time warmest Christmas set back in 1982 by 1-degree. The New York City warmth will not be alone…" Ventrice wrote in a blog post.