Thursday, October 20, 2011

Hints on the Winter Weather Outlook for Cleveland

We use a tossed salad of variables in determining our winter weather outlook. The northern Pacific Ocean, central and tropical Atlantic Ocean offers some great clues as do the tropical patterns that stretch from central Africa over the Indian Ocean eastward over the central Pacific Ocean.  The upper atmosphere over the tropics reveals connections to jet stream position which dictate how variable the cold, arctic intrusions will be over the Great Lakes.  By analyzing these variables from past winters, we come up with the "best match" that  fits the upcoming winter for Cleveland and Northeastern Ohio.

Dividing up the winter into two parts gives a bit more clarity to the winter outlook. 

First November and December and early January:

One of the main drivers of our weather patterns are from ENSO or the changes in the tropical Pacific Ocean sea surface temperatures better known as El Nino (warmer than normal) or La Nina (cooler than normal).

Based on these parameters above, the years that match up fairly well are:


Add up these winters NOVEMBER, DECEMBER AND JANUARY to come up temperatures compared to normal would be:

Andre Bernier has an excellent blog post on the "tricky, harder to predict" variables of winter. These variables all describe changes in the arctic and the north Atlantic which are more random than ENSO. You will notice that in the years these Arctic and north Atlantic factors were the strongest/coldest--early 60s, mid 1970s--(see Andre's first graphic), LA NINAS WERE PRESENT which fits this upcoming winter.  One of the strongest La Nina periods in recent times was the mid 1970s and we all know, if you are from Cleveland, how snowy those winters were!  These "wild cards" will play a significant role in how and when the arctic air pushes south and, early on, when and how much lake effect snow we will receive.

Watch what happens when we ADD the years in the mid 1970s where a weak to strong La Nina persisted with VERY STRONG/COLD ARCTIC patterns which subside in January, February and March:   THOSE WINTERS FEATURED NEAR NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES FOR NORTHERN OHIO!

Let's hope for this weaker arctic pattern to return later this winter with its drier, less cold air in January and February. That should allow for the snow cover to melt which would keep the snow mold from forming on our lawns as it has in recent winters.

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