Shades of El Niño

It's almost as if Minnesotans are living on the dark side of the moon. The rest of the planet has lived through two of the top five warmest years on record; 2013 was the fourth warmest year on record globally according to the National Oceanic and Atmospheric Administration.

This year is almost certain to finish as the warmest year on record globally. Minnesota has been on the cold side of the planet for nearly two years now. The epicenter of global coolness.

So what's causing our sudden shift to a dramatically warmer weather pattern?

The odds are growing that we can blame it on a rapidly developing El Niño. Check out the growing smudge of warmer than average waters in the tropical Pacific.

NOAA

Tropical Pacific Ocean water temps have been well above the 0.5C threshold that defines El Niño conditions for a month now. NOAA and others are waiting for other atmospheric signs that a full blown El Niño has developed before they make the official call. But atmospheric circulation patterns don't seem to be waiting for that message from NOAA, they're already acting like there El Niño is in progress.

Case in point? A persistent west to east (zonal) upper air flow pattern across the United States this month.

NOAA

A series West Coast storms with heavy, drought denting rains and mountain snows in California and the West Coast.

NOAA

And unseasonably mild December Pacific breezes across the U.S.

NOAA Climate Prediction Center

If it walks like a duck and quacks like a duck, it might just be an El Niño duck.

December thaw kicks in

In the short term, our weather week starts on seasonably cool notes. But by Wednesday afternoon, you'll notice something has changed. The sun and the breeze feels warmer. By Thursday you'll feel the thaw kick in. Friday afternoon temps shoot into the 40s, It will be clear is not your typical Minnesota December.

Here's The European Centre for Medium-Range Weather Forecasts model surface solution by Friday evening. A well established southerly breeze pumping unseasonably mild air north into Minnesota, and even Canada.

Montreal Weather Centre

The magnitude and duration of the coming thaw may still change a bit, but the pattern I've been highlighting for nearly two weeks now is here and there's no doubt it will get much, much warmer later this week.

Weatherspark

Pretty much all the snow cover in central and southern Minnesota will be history by Sunday.

Will we squeak out a white Christmas?

Stay tuned.