Wednesday, December 2, 2015

Winter Weather Outlook

Winter is officially on the clock with the start of Meteorological Winter on December 1st.  I've called your bluff Old Man Winter and time will prove this true. A colossal El Niño will dominate.   El Niño, which is classified by the warming of the equitorial Pacific waters off the coast of South America can and does alter global atmospheric circulation.  Typically, this ties the polar jet stream up north into Canada which can significantly limit the frequency and intensity of cold air outbreaks. The impacts of such an occurrence have driven our winter weather pattern in the past and will very likely dictate our winter weather this year too. 

Here is a look at historical El Niño winters.  Since 1950, there have been five "Strong" or "Very Strong" El Niño years:

El Niño Winters:

1997-1998
1982-1983
1972-1973
1965-1966
1957-1958

El Niño Winter Temperatures
 Every winter with a strong or very strong El Niño resulted in a warmer than average winter.  The strongest El Niño on record during 1997-1998 brought an exceptionally warm winter that averaged nearly 7 degrees above normal!  Do you remember this winter?  I do! Winter snow rarely, if ever covered the ground and spring flowers bloomed in January.  (I recall playing golf TWICE in January!)
El Niño Winter Snow
 Snowfall during the 1997-1998 El Niño resulted in less than 4" of snow for the entire winter!
After two historic and brutal winters the past two years that brought all time record snow -- 86" of snow in the winter of 2013-2014 -- and frigid record shattering cold --3rd all time coldest calendar month on record in February of 2015 -- winter this year will bring a welcome change.  The winter outlook for our area will be warmer than normal with below average snowfall.

Winter Temperature Outlook
 +2 to 4° Above Average 

Winter Outlook Temperatures

Winter Snowfall Outlook
15 to 20" Below Average (About 50% of Normal Snowfall)

Winter Outlook Precipitation
This blossoming very strong El Niño will drive very mild weather this weekend and through next week. Much, if not most to the United States will be well above average through the middle of December. 
GFS Temperature Anomaly valid Thursday, December 10th
While any winter will feature some snow and cold, that is inevitable. Occasional cold snaps or even the possible snow storms are part of any winter.  These can and still will happen.  There are several factors beyond El Nino that can influence winter weather.  But, overall, get used to the more regular mild winter weather that lies ahead this season.


~Meteorologist Chris Vickers