Will 2013 Come In Like a Lion Or Lamb?

We barely missed our white Christmas.  Cincy to Louisville to Owensboro to Paducah...basically the Ohio  River is where the snow line set up.  North and west of there...you had a blizzard.  On the Kentucky side of the river...misery as we dealt with cold rain and fog.

So let's look toward January.  A new year promises to bring new weather.  But will it be snowy and cold, or warm and dry?

One thing to consider is that the Arctic Oscillation has been negative for all of December.  The last time it went positive was early November.  As a result, November featured a lot of days in the 60s here in Kentucky, and even one day that hit 70 at Lexington.  November was also snowless, with none reported for the month.  And finally it was dry with less than two inches of rain for the entire month.  You see, when the Arctic Oscillation, or AO for short, is in it's positive phase, you don't get those wild swings in the jet stream.  And when you don't have a wildly meridional flowing jet you also won't get big powerful storms.

December saw the return of a negative AO and wild weather...it's just that it all barely missed Kentucky.  From tornado outbreaks in the deep south to blizzards in the Ohio Valley, we saw the return of the wild weather which was to be expected.

Looking toward January, the current forecasts for the AO index are for it to go positive again.  Some outlooks even show it going strongly positive.  At the same time, the NAO is predicted to hang out close to neutral.  The NAO being in a negative phase can lead to huge troughs in the eastern U.S. that are good for snowstorms.  With a neutral to positive NAO you don't get those big troughs.  The AO being positive adds to the lack of storminess.  Here's a look at the current AO forecast:

See how during the first week of January the AO starts to go positive and may do so in a drastic way?  If I was a betting man..  I'd say that this is a signal that at least the first 2 to 3 weeks of January 2013 could end up relatively calm across the eastern U.S.  We may not see any big snow storms in Kentucky at all during this time.  There is a chance that the temperatures could remain average to slightly above average during this timeframe also.

As of today, we're looking at a rain/snow mix on Friday night and into Saturday morning...ending as snow showers on Saturday.  Then another storm may bring snow to us for New Year's celebrations.  Let's hope that we put down some snow before January...because it's not looking good for snow lovers right now.

My winter outlook is taking a beating.  Winter is far from over, however.  Some of the worst winter storms in KY's history have occured in February and March.  Hang in there...


-Shawn

Christmas forecast for central Kentucky

Well, we were holding onto hope that a white Christmas would pan out for the Bluegrass this year, but it looks like it's not going to happen in 2012.

Recent trends in the model data have been to take areas of low pressure on a track toward the Great Lakes, rather than moving them across the southern tier of the nation.  The GFS, as always, has been showing this idea for a while now.  Overnight, the European model came on board and it is now showing the warmer solution also.

Check out the forecast for the end of this week on the European model:

Notice the low moving into the lakes.  This will force a strong cold front through the area, with some thunderstorms along the front.  The GFS model agrees:

Notice that behind the front, we may see some flurries or possibly light snow showers...but this is not going to be a big snow event for Kentucky.  If you get a dusting on your car and in your yard, consider yourself lucky.

Then we look toward the following week.  After a relatively dry and cool period around Christmas, another storm looks to blow through the area on Thursday and into Friday after Christmas.  The European model again is taking this storm into the Great Lakes from the midwest.  Here is the low sitting in Oklahoma on Thursday night, about to make it's turn toward Michigan:

And just look at those temperatures..  very warm in the eastern U.S.  Basically a repeat of what we will see later this week, played out again next week:

Like I said, GFS model has been superior in showing this solution earlier, and it agrees with the Euro.  Rain and storms after Christmas could possibly end as a flurry or two as the storm moves through the  Great Lakes.

It is interesting to note that the indices were all forecast to go negative.  If we can get the PNA to go positive then we might get into a setup where the trough would dominate the eastern U.S...but right now it's starting to look like that's not going to happen.

As always, I'll keep an eye on things.  There is a ton of cold air bottled up in Canada and it would just love to spill into the OH Valley if given the chance.  Let's hope that the pattern will give it some incentive to do so in the coming weeks.  :)

That's it for now.  Enjoy the week.


-Shawn

White Christmas in Kentucky?

Well we've almost got the first full week of meteorological winter under our belts.  It's time to start looking toward Christmas, and particularly at our odds of seeing the sought after "white Christmas".  To date, it's been fairly mild overall.  We've seen some rain, but November was a dry month compared to average.  Temperatures have been running close to normal, or slightly above.  Winter hasn't really made its self known around these parts yet.  But according to all the major computer models...that is about to change.

Notice how far north the jet stream is right now:

Now look at what happens by the week before Christmas:

See how the pattern has drastically changed?  Now the jet is flowing across the southern U.S. with a cutoff low spinning over Maine.  This will allow some of the cold air that's been bottled up in Canada to spill into the Ohio Valley.  Here's where it gets interesting.  At the same time that's happening, a low pressure area may kick up on the Gulf coast and spread moisture northward.  If this happens, it would cause snow to break out across Kentucky during the weekend leading up to Christmas Eve.  Take a look at the GFS representation:

As that storm works into the Carolinas, it spreads heavy snow into Kentucky.  This is still two weeks away and there are a lot of variables on the table that will make or break this forecast.  Don't get excited about this just yet.  My point here is this:  the cold air is coming and the chance of a white Christmas in Kentucky is still looking very good.  Fingers crossed!

-Shawn

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.

-Shawn

Record Cold in Kentucky; What Does This Mean for Winter 2012-2013?

Hello and welcome to winter...er, I mean, fall.  Temperatures over the past 10 days have been more reminiscent of late October than September.  In fact, yesterday we touched 37 degrees in Lawrenceburg.  This morning many of the Kentucky mesonet sites hit the freezing mark.  In many towns this is the coldest start to September 24^th we’ve seen in almost 90 years.  And the record setting cold might not be done just yet.

 

Temperatures this week will modify and southerly winds will bring a little more humidity to the air.  It will feel more normal for this time of year. Thunderstorms may also move through KY on just about any day this week as a slow moving front sort of stalls out near the Bluegrass.  The last week of September looks to go out pretty nice overall.  We could still use some rain and we should get at least some rain this week.  Enjoy the warmth, because there are some signs that this week may be the end of warm weather for 2012.

 

Next week, the computer models are indicating that a couple more large troughs could sweep into the eastern U.S. and drop our temperatures once again as we start to get into October.  Areas that didn’t see frost this morning will have another shot at it by the end of next week.  A lot of folks are wondering what this means for winter.  A cold pattern is already setting up here in our part of the world and it’s still September.  Let me preface this by saying that nobody has proven any ability to accurately forecast winter from months away.  It’s just not yet possible to make accurate winter forecasts.  Having said that, early indications are that the eastern half of the U.S. including Kentucky may see a cold and snowy winter coming up.  There are a lot of global indices and patterns showing signs of this.  It is too early to make a winter forecast right now, seeing as how we just began astronomical autumn a few days ago.  Next month I’ll do a more detailed look at what winter 2012-2013 may have in store for us.

 

The official government forecast, just for grins and giggles, calls for mild and dry weather throughout winter (December-February) in Kentucky.  Obviously they are interpreting the signs that are showing up in a totally opposite fashion compared to all the private sector weather forecasting companies.  But here’s a look at what they’re going with:

 

Temperature is above average for winter:

 

 

And precipitation is predicted below average for winter:

 

 

 

Interesting, huh?  Like I said, this is one forecast and there are many signs pointing toward just the opposite.  So let’s give it another month of fall weather and look at the data again and then I’ll put out a winter forecast.  Take care and enjoy the weather this week...it’s going to be nice!

 

 

Shawn