Wednesday, October 10, 2012

Kentucky Winter Forecast - 2012-2013

Update 22:00 30-October-2012:

The Climate Prediction Center released an updated statement today emphasizing that neutral ENSO conditions are continuing.  However, weak El Nino conditions are still forecast to develop within the next month.  Weak El Nino conditions are predicted to carry us into the heart of winter, and then we may go back to neutral conditions again.  I have attached a graphic below showing that the La Nina conditions of last year are not going to be a factor this year.  One thing is for sure...with a flop in the ENSO conditions from last winter and the fact that we've already seen huge blocking in the NAO index...this winter is continuing to look like a much more active one than last year.  Hang on..I think the ride is about to take off.

Image is courtesy of NOAA's Climate Prediction Center, National Centers for Environmental Prediction.

My second semester at college, in early 1998, a severe winter storm struck Kentucky.  Over 20 inches of snow fell in many KY counties, aided by a process we call dynamic cooling.  To folks in the Lexington, KY area, this storm came to be known as the infamous "dusting" in reference to a forecast made by the late Brian Collins, meteorologist at WKYT-TV, the night before the storm struck.  Bowling Green, where I had just moved, saw about 8 inches of snow.  That was quite a rarity for the area.  I walked almost a mile, uphill, in deep snow, at 7:45 in the morning to get to class...and no, that's not a joke.

The year my wife and I married, in late 2004, the weather turned fierce and once again a major winter storm struck Kentucky.  Louisville saw almost two feet of snow in many places.  Paducah set a new record with 14 inches.  After Christmas, the temperature plummeted to well below zero.  Winter came in like a lion and it was brutal.

The winter of 2009-2010 was an exciting one as well.  December came in strong with a wind storm that produced snow and wind gusts to 55 miles per hour right here in Lawrenceburg.  We had another storm on Christmas day that brought rain and wind gusts above 30 miles per hour.  We also saw a freezing fog advisory the week before Christmas, which is unusual around here.  January finished up almost 4 degrees below average for the month, with almost 10 inches of snow.  February was also wild that winter, with a tornado outbreak on the 11th, as well as almost 5 inches of snow for the month and numerous wind storms, one which produced damaging gusts over 50 miles per hour again in Lawrenceburg.

So what do all these years have in common?  The answer:  El Nino.  El Nino refers to the general warming of the pacific equatorial waters, and the effects this warmer water has on global weather patterns.  We typically see the biggest results of an El Nino event during the winter months, which is why the ENSO (El Nino-Southern Oscillation) cycle is so critical to winter forecasts.  Generally, we go into an El Nino phase every 3-7 years.  As you can see, El Nino events have brought very wild winter weather to the Ohio Valley in recent history.  The one that occurred in 1997-1998 was the strongest one ever recorded.  Another consequence of an El Nino year is that tornado outbreaks the following spring are more common, and coming out of the 1997-1998 El Nino Kentucky did indeed have a serious outbreak on the 16th of April.  One of those storms caused $512 million in damages to the city of Bowling Green.

As we head toward winter once again, people as always are curious; what does this winter hold in store for us?  Well, an interesting piece to the puzzle this year is going to be the return of our good friend El Nino.  There are many pieces to the winter forecast puzzle.  We look at things such as the Atlantic Oscillation, the North American Oscillation, previous analog years that may give us clues, the current status of drought and ground water reserves in the U.S., etc.  There is no doubt, however, that the status of the ENSO cycle is a huge key to what is in store for us.

The current projections call for El Nino to be weak to moderate as we head into winter.  This bodes well for the snow lovers in the area.  Another thing to consider is that history is also on our side.  The decades of the 1950s, 1970s, and 1990s all featured some severe winters.  That would put the 2010s in line to follow suit at some point.  There is also a japanese seasonal weather model that accurately predicted the winter weather we saw last year in the eastern U.S.  When all other forecasts busted...this weather model was onto something.  For this winter, it's predicting a reversal of what we saw last year.  It is predicting cold and snowy conditions to prevail in the eastern part of the nation.

With all the signs looking great for cold and snow, I'm confident in making an early forecast for above average snowfall for Kentucky this winter.  I think we'll see snow in each month from November - March, with possible snow storms with heavier amounts in January.  I think that temperatures will be slightly below average during the December - February period.  And finally, I believe that the risk of ice storms will be slightly above average due to the general storm track being pushed to the southern tier of the nation in response to El Nino conditions.  I do not believe that a mild winter is coming up like the one we saw last year.  If the forecast works out, the economy will be looking up for companies that make snow shovels and sidewalk salt.

I will try to update the forecast with some visual charts and maps in the coming weeks.  Take care and enjoy the beautiful fall colors this year thanks to the frequent rainfall we've gotten recently.



  1. Shawn,

    Great forecast. I am curious to see if you think we're either diving into a neutral winter, in terms of ENSO. El Nino seems like it's dying rapidly...and some are even saying La Nina will return later in the winter. I'm not sure...getting mixed signals. Rooting for El Nino, though! :) Hoping another 2009-10 comes our way...

  2. Yes the signals are hard to read...but I still think La Nina is a no show this year.