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