It's the time of year when lovers of cold and snow start to get excited as visions of blizzards and bitterly cold temps dance in their heads.
"What kind of winter will we have?" is the question I hear the most, and that usually starts in the summer. It's time to give you an answer with the 2011-12 winter forecast.
First, let's evaluate where we've been and where we are.
We're in the midst of our coldest and snowiest winters since the late 1970s. That's the last time we put together back-to-back average winter temps below 32 degrees and the last time we recorded 20 or more inches of snowfall in back-to-back winters.
In 2009-10, we had an average temperature of 30.7 degrees and 23.7 inches of snow; in 2010-11, we averaged 31.5 degrees and recorded 27 inches of snow.
Can we make it three colder-and-snowier-than-normal winters in a row? The short answer is yes, and here is why.
To start with, the current state of the oceans point toward colder temperatures.
The Atlantic Ocean shows a configuration of colder and warmer water that should favor a North Atlantic Oscillation. This would favor blocking high pressure over Greenland, helping to force cold air from Canada south into the states.
We continue to see a strong Pacific Decadal Oscillation. This features colder-than-normal water temps along the west coast of the United States into the northern Pacific near Alaska. (We have been in a Pacific Decadal Oscillation phase for the past several years.)
Meanwhile, the biggest driver is sitting near the equatorial Pacific Ocean. La Niña is alive and well for the second fall and winter in a row. This is when the waters in this area run colder than normal over a wide region. The forecast models all show those temperature anomalies lasting into the winter months.
I looked at all of that information and other variables and checked for past years that had similar features. This allowed me to see how the winters following those years turned out, giving me clues about how this winter might fare.
I also checked the stats for those years to see whether any of them matched the actual weather we're experiencing here.
Of all the years I've looked at, 1950 seems to be the closest match to the actual weather and global indexes. That year featured a cold and snowy winter for Kentucky and included several big events. (It is important to note that no two winters are ever alike and never play out exactly the same way.)
One final thing to take into consideration is the fall snow cover across the Northern Hemisphere. The greater the snow cover, the better the chance the winter air will be colder than normal. Snow cover right now is much above normal.
Here's the breakdown of how I see our winter forecast:
I expect our temps to average 1 to 3 degrees F below normal for much of the state.
December and January are likely to see the coldest departures from normal, with moderation to above-normal temperatures possible for February. Wild swings in temperature are a good bet, and I expect a few severe cold shots that will take our temps below zero.
Snowfall should average above normal for the entire state. Lexington averages about 14 inches of snow each winter; this winter should bring totals in the 20-inch to 25-inch range. This is a year likely to feature several "clippers" diving in from the northwest. These winds usually produce light snow. However, the Great Lakes are much warmer than normal, and this means a likely increase in snow showers and squalls brought by the clippers.
Here's hoping you get as much or as little snow as your heart desires.
My weather blog (weather.bloginky.com) will be with you every step of the way with frequent updates each day.
Feel free to leave your thoughts on the winter ahead, and keep checking for daily updates. Happy snow tracking, and take care.